Marilyn,
Eeeeeeeewwwwww about the yellow liquid...and I'm sure that did it for the Rubbermaid bowls, huh?!
I'd buy safety-locks, too!
LOL, isn't that the truth...the child-safe stuff is such a challenge for us adults!  The kids can figure out how to get around it, but we struggle (at least cats struggle along with us!).  LOL, I still have trouble with child-safety caps on meds.  ;D
How cute...I wish you had a video of the cat snagging the twist-ties too!  Their antics are soooooo adorable.  I can think of a few I'd like to have of ours, as well, like one of her drinking out of hubby's cup.  LOL...she decided the water there must taste better, and she tried to stick her whole head into the cup.  Ultimately, she realized she couldn't drink that way, so she dipped her paw and then licked it off.  So cute!  (By the time I pulled out the camera, though, she had decided putting her whole face in the cup was better.)
She also has another thing she likes to do...to have me hold her water bowl up for her (because it tastes better, of course!).  So the other day I was doing that, and she decided to do the dip-paw-in-the-water-and-lick-it thing.  She soon tired of that and switched paws!  How adorable.
They do know how to entertain us! 
Melanie  (known to the cat as "Rowr" or "Rowr Rowr") =^.^=

Melanie,
The child-safety locks didn't go on to keep her out of her treats. They went on because of the yellow liquid I found in the Rubbermaid bowls..twice!!  I have no idea what caused her to do that, but I wasn't going to put up with it happening a 3rd time.  The saftey-locks were cheaper than new fasteners. There were enough of them in the package that we put them on all the cabinet doors.   We had to re-train ourselves on how to open a cabinet door.  
Before we got married, my hubby kept the twist-ties off bread bags in this one particular drawer. The kitty figured out that she could open the cabinet door below the drawer and somehow push against the back of the drawer to get it open. Then she would hop up on the counter and reach down into the drawer to snag herself a twist-tie.  I think it would have been fun to watch her do this.  Too bad there wasn't a way to get a video of it. 
Marilyn

Marilyn,
I imagine the curtain running along the curtain rod can sound quite scary to a little one!  Same with the shower spray running full blast.  I do know that many cats love to have a sink faucet running a small stream...years ago in another area, some neighbors used to have us watch their cats when they went away on vacation.  Well, we learned that the one cat just LOVED a small stream of water in the bathroom sink.  He'd play and play.
So the one time they went away on vacation, we gave the cats a little more attention than usual, especially running the water in the bathroom sink for the male cat.  And then the cats' humans returned, and they said, "What did you do to our cats?"  Which made us wonder what we'd done wrong, until we found out it was just the opposite...normally, when they'd return from vacation, the cats would give them the cold shoulder for about a week.  This time, the cats' attitude was, "Oh, you're home...that's nice."  A total non-issue.
All we could think was that by running the water for the one cat, it made them feel like their humans had been home all along!
Yes, I caution my husband all the time NOT to give the cat people food.  He's a little more lax about it than I am.  I'm ultra strict.  Mind you, when I was a kid, I'd feed the cats whatever they'd eat, and I'm sure they had many things they shouldn't have (only because I didn't know better), but now I won't feed the cat anything I haven't checked out.  As for the syrup, it's only a tiny bit, just a couple of licks.  And when I say "fake syrup," I mean sweetened with Splenda.  It hasn't seemed to cause her any issues, and as I mentioned, he only lets her have a couple of licks of it...but she sure loves it!
She also loves sunflower seeds...go figure!  I won't let him feed her more than three or four a day.  I've read they're okay, but am still cautious.
Good idea about the child-safety lock!  I know cats can and do sneak into cabinets to get to their food.  I think if ours could open the refrigerator, she'd get her own food - well, at least she'd ATTEMPT to do so.  And she does know where it is in the fridge and has tried to pull on the door (except she can't get it open!).  The thing is, once she'd get it open, she'd then have to figure out how to open a drawer.  She can see into the drawer (it's clear) and knows that's where her food is, but I don't think she's quite figured out how to get that drawer open!  (And if she did, she'd still have to be able to reach down into it and pull her dish up and out...the dish is a fairly heavy ceramic one.  She'd also have to pull the foil off.  She hasn't quite figured out foil!)
Melanie  (known to the cat as "Rowr" or "Rowr Rowr") =^.^=

Melanie,
Our kitty is a little weird about shower spray. She doesn't want to be in the bathroom when hubby has the shower running, yet she's come in a few times when I've been in the shower. I think it's because he has the water running full blast. I turn it down a little.  ....She doesn't like the sound of the shower curtain being pulled along the curtain rod, so she'll run out when she hears it. But she comes back when she thinks it's safe.
The kitties back home would eat just about anything you offered them. This kitty is a fairly picky eater. That can be a good thing. It's a little easier to figure out what she can and cannot tolerate.  
I think sometimes those weird food can cause tummy issues for the kitty. It might be a good idea to be careful with the fake syrup. Does it contain sugar alcohols? They are designed to not be completely absorbed into the human body, to just pass on through. The labels usually warn they may cause diarrhea. I have no idea what sugar alcohols might do to the kitty tummy.
Oh, yes, our kitty knows where her treats are. She could probably get them out herself if there weren't a child-safety lock on the cabinet door!
Marilyn

Marilyn,
ROFL...no doubt the cat can count!
Honestly, I think they're far smarter than many give them credit for being.  Just because they can't really speak and sometimes don't quite "get" certain things doesn't mean they're dumb!  They know where certain things (like food and treats) are kept (ours knows the spot where her treats are kept, as well as her wet food) and ours has learned how to say "hi" and "hello" - distinctly!  I don't call that dumb.
Yes, ours doesn't really like the sound of the shower spray, either.  She won't step INTO the shower...she'll just stand outside in the bathroom!
Your hubby has the right idea...yuck, who'd want to be covered in cat hair after a shower?
Does yours also like to eat weird foods?  Our girl LOVES sunflower seeds.  She also likes licking the plate after hubby has pancakes...when he puts fake syrup on them.  It's so funny to watch her after she's had the syrup...she can't quite get around that stickiness! 
Melanie  (known to the cat as "Rowr" or "Rowr Rowr") =^.^=

Melanie,
Our kitty isn't too crazy about the sound of the shower spray. She's always ready to come in when the water is turned off, though. She's all friendly and wants to rub her body against your legs. Hubby keeps the door shut 'til he's had a chance to dry off so he won't be covered with cat hair. 
This kitty likes to remind me which cabinet has her treats. Well, she thinks of them as treats. Really they're for hairball control. It's funny how she watches me count them out. One time, I was running a little low on them and was doing some rationing. When I gave her one or two less than usual, she looked at me ...looked at the treats ....looked at me again, then went ahead and ate the treats. Later, I told hubby "I think the cat can count." 
Marilyn

Marilyn,
LOL!  Your little one sounds like so much fun!
Ours likes the shower, but so far hasn't been brave enough to step in.  She's stood outside and likes to be in the bathroom when one of us takes a shower, though.  She also sits on the rug at various times, usually when nobody is in there.
The other day, I was in the bathroom and heard scratching at the door, so I had to let her in!  Odd little bugger.
That "watching for something to happen" is what our kitty does, too!  She looks at the refrigerator door, as if watching it is going to somehow make it open.  She doesn't understand...no, it will not open by itself...it needs a person to open it.  Though she does know exactly where her food is, and I often thank her for leading me to it, reassuring her that I couldn't have found it without her help. 
I agree...they entertain themselves well enough...LOL, though I don't think ours quite got the memo that it's okay to do this.  She wants us to entertain her!
I can see the appeal of those milk jug rings.  I imagine they're good for biting, too.  Ours definitely likes biting toys and things.  One of her toys, a small stuffed dog with a bell on its tail, has had his share of biting.  She's also done that with a ball.  Chirpy bird...nope...she's bitten on his cage a couple of times, but leaves him alone.  Go figure!  If I were her, I'd find him terribly annoying.  ;D
Melanie  (known to the cat as "Rowr" or "Rowr Rowr") =^.^=

Mealanie,
I've found that cats can entertain themselves fairly well most of the time. Another "toy" our kitty likes is the ring that's right below the lid of a milk jug. It slides across the kitchen floor pretty well. With the added benefit of making more noise than ponytail holder "rings". 
Lately, our kitty is working on training us to turn on the water faucet for her. When either of us in the kitchen, she'll sit at the sink and stare at the faucet. We usually give in and turn it on to a fast drip for a couple of minutes so she can lap at the water.  She's taken to following hubby into the bathroom and sitting on the vanity, staring at the faucet 'til he's ready to wash his hands. The other day she was sleeping on the sofa and still managed to hear him go into the bathroom. She leaped off the sofa and ran down the hall so she could be at the sink when he got there to wash his hands.  ....I wonder if there's some kind of motion-activated "faucet-turner-on-er" out there somewhere.
Marilyn

Marilyn,
Beating you to the ignore, eh?!  ;D
Ours is usually at our heels...most of the time.  She can't bear to be alone in a room...unless it's under her terms, of course!  She'll go from a sound sleep to joining us in whatever room we're in at the time.
Glad your kitty was able to retrieve the ring from under the stove!  That's a lot better than you having to do that (though it certainly delays the Training Our Humans program a bit, eh?).
LOL, oh, they love those hiding spaces!  We chased the little one around today...she gets her wild streaks, so we chase her (making noise with our feet) and say, "I'm gonna get you!"  At first we were worried she might actually be afraid of us, until we realized she was coming back for more...doubt she would do that if she was afraid!  Anyway, today she ran into the other room, and we couldn't find her!  We let her be, and ultimately, she appeared from wherever she'd been.
Surprisingly, she hasn't hid her toys...but then, she's lost interest in almost all of them. 
Melanie  (known to the cat as "Rowr" or "Rowr Rowr") =^.^=

Melanie,
I've done the paper towel roll, too.  It worked at first, but she hasn't played with it for quite a while. Sometimes the things we think she's lost interest in will be in a different place in the morning than they were the night before.  I guess anything looks good when she's bored.  ....She seems to keep going back to her "rings".  While we were eating supper last night, she took her ring out of the food bowl and knocked it under the stove. She played around and pulled it back out again. As longs as she doesn't hit it too hard, she can rescue it herself.   Every now and then a ring I haven't seen in a while will appear again. I guess she had it in a really good hiding place.
A minute ago, the kitty was having a fit at the door. I opened it to see what her problem was. When I looked down, I saw one of her "toys"--a strip we pulled off of a box to open it. I think it's her way of saying she wants her human to be in the same room so she can ignore said human. 
Marilyn

Marilyn,
ROFL!  They do love to make us do odd things, don't they?  (I believe they call it "Training Our Humans.")
That's so funny about counting the rings!
Crinkly bags...yes, ours would do the same.  She gets spooked out by some noises, and crinkling would be one of them.  For a long time, she wouldn't go near a certain toy that had a little jingle bell.  It seemed to creep her out.  (Now it doesn't, for some reason.)
Funny you should mention playing with trash.  The chirpy bird toy lasted maybe all of two days.  Yet when she gets into her wild moods, she'll pounce on simple pieces of paper!  (I've balled up unused coffee filters, which are softer than paper...she liked batting those around a bit, then lost interest.)
My childhood cats had two favorite things: pencils and rubber bands.  I'm afraid to give our little one those things, because though she likes playing with both, we don't want her to go crazy and hurt herself or swallow a rubber band.
Oh, another fun thing...I crocheted a chain with a bumpy thing toward the bottom.  She ultimately loses interest in it, but it lasts the longest of anything I've tried, so I retire it for long periods of time and then bring it out again...and it's all fresh and new to her, LOL.
The tissue box toy sounds like a big hit!  I'll have to try that.  I've tried medicine bottles with things in them to make noise, but they didn't seem to spark her interest.  Nor did half of a paper towel tube, which one site had said made a GREAT cat toy.
Melanie  (known to the cat as "Rowr" or "Rowr Rowr") =^.^=

About the noise from the crinkly bags--I'm hoping that bags stuffed between 2 layers of crochet will be greatly muffled.  If it was too noisy, she might not want to sleep in it.
Our kitty has a chirpy bird, too.  It didn't hold her interest very long. She plays more with what most people think of a trash. She enjoys an empty tissue box. When it first went empty, I cut out the Boxtop for Education that was on the bottom, cutting just the square. I took the strip I tore off the new box and folded it in half lengthwise, and after tearing out the plastic from around the hole on top of the empty box, I put the folded strip through the holes. The kitty can wiggle the strip from the top or the bottom. She's managed to get the strip out a time or two, but I put it back in again.
Another thing she really likes is ponytail holders.  One that she goes back to a lot is black covered elastic. She likes slapping it around under the table, among the chair legs. Sometimes we find it outside our bedroom door when we get up in the morning. I have even found it on the floor inside the bedroom, where she's pushed it under the door. Trying to get us to play with her, I guess.   She also really likes the smaller terry-like ponytail holders. I bought some years ago with metallic threads that didn't work on my braid. (They'd stretch out and stay that way.)  The kitty has 4 or 5 of them in different colors. I put them in this one spot for her. When she feels the urge for a snack, she picks up a ponytail holder and goes to the food bowl, drops it in and starts munching. Sometimes, she'll drop it in the water bowl and fish it back out before dropping it in the food bowl.  And every now and then, she drops it in the water and leaves it.  You can tell how many times she's had a snack by counting the "rings" in her bowl.    ....Sometimes she'll take a "ring" and bat it around the kitchen floor and it ends up under the stove or the fridge. When shes gets down to one, I'll get the yardstick and flashlight and go on a hunt. When she sees these tools, she knows what I'm doing so she sits and watches me get down on my hands and knees, the side of my head on the floor searching for "toys" under the appliances.   .....More entertainment for the cat.  "Looky, what I can make my my human do."   LOL
Marilyn

Marilyn,
Thank you for the link, and I agree with you...while they're cute, for over $100, they aren't that cute!  (LOL, I think I like the kitties a little more than the caves.)
Though I would love to have a pattern to make one!
Please do let me know what insights you have into the makeup of those cubes.    Foam is a very good possibility, and one I hadn't considered.
LOL about the same idea for the sides...GMTA!  ;D  If kitty likes the crinkly sounds, that would be a terrific idea (hee hee, just make sure she doesn't keep you awake at night with all of the noise!).
BTW, kitty here has a little toy graveyard thing going on.  She has a very noisy bird in a birdcage, which, if tilted just right, makes chirping sounds.  So far, it hasn't made noise at night, and hopefully it won't before the speaker stops working!
She's too darned smart for it.  At first, she was enticed when we made the little bird in it move around.  But after a couple of times of this, she caught on.  LOL, no fooling her!
Melanie  (known to the cat as "Rowr" or "Rowr Rowr") =^.^=

Melanie,
Hey, you're good. My thought about firming up the sides was to make another layer on the outside of the current one and stuffing it.  I wondered if plastic shopping bags would work for the stuffing. I've got plenty of them and the kitty likes the crinkly sound they make. It should still be washable.   I haven't had a chance to experiment with the bed because the kitty spends so much time in/on it.  When it warms up a little more, I'm hoping the kitty will find a new snoozing place for long enough to let me do some work on the bed.
I've seen kitty cubes like you describe. I think there's some foam inside there somewhere. It holds a shape a little better than just stuffing.  I've never picked on up, though, to see how heavy they are. They don't look like they weigh enough to have wood inside them.  A single piece of cardboard is pretty flimsy, but if the cardboard formed a box, it would be sturdier. Our kitty has hopped on to empty boxes without them collapsing. But this kitty only weighs about 6 pounds.  ....Hmmm, when I see one of those cubes again, I'll try to remember to poke it so maybe I can figure out what might be inside it.
Over on Ravelry the other day, I saw a link to a place in Germany where they sell "cat caves". They looked sorta like two big circles made out of wool that were felted. Something was put inside to hold it open while it dried, which helped to form the mouth of the cave.  If I can find the link again, I'll copy it into a message to you.  These things were cute, but I think someone said the price was over $100 USD.  They weren't that cute!!
Marilyn

Marilyn,
Please tell me if you come up with something...I've been trying to think of the same thing!  I saw the cutest little kitty cube in the store the other day, but at $15 for such a simple item, the thought occurred that I can knit or crochet one myself...if only I can figure out how to support it!
In the case of your wonderful kitty bed, how about doubling then sides (e.g., make another layer of side stitching and connect the top pieces), then firmly stuffing this...might they then stay up better?
For a kitty cube, I was thinking of cardboard underneath, but I hate that idea, since it collapses so easily, especially under the weight of a 10+ pound cat.  (I'm guessing the one in the store does use cardboard, perhaps...so does that mean it collapses easily?    )  Wood is too heavy, though.  Sigh, still have to think about this one.
Melanie  (known to the cat as "Rowr" or "Rowr Rowr") =^.^=

I can't believe it's taken me so long to say "thank you, guys" for your nice comments.  The kitty spent quite a bit of time in her bed while it was cold.  Now that it's getting a litte warmer, she's adding a little more variety to sleeping places.  Sometimes she sleeps on the bed because the sides have collapsed.  I want to try and figure out a way to make the sides a little more firm so they will stay up.  I'd like to have it done by the time cold weather arrives in the fall, so I've got time to do some thinking, in case my first idea doesn't work out.
Thanks again.
Marilyn

What a good idea and how cute.

very cute!! pepper
 

Marilyn,
What a beautiful job you've done, and how cute the cat looks in her bed!  I love the way they snuggle up like that.  LOL, obviously, the bed is a hit...four paw prints of approval! 
Melanie  (known to the cat as "Rowr" or "Rowr Rowr") =^.^=

Purrfect fit!

Charlene