I also like taking old toilet paper/paper towel tubes, poking various holes in them and stuffing them with hay, treats etc. Ginny prefers the twigs, she likes to play with those though George will usually chew them down to shreds before she can have all her fun with them. Fred doesn’t play very much, he’s a little odd though if you put a bag of raisins in front of him he will not stop until he has figured out how to open it.
George loves blankets/towels. He doesn’t usually eat them, though I do keep a close eye on it. He just likes to bunch them up and wait for me to come by and straighten it out again for him to play with (though he does put considerable holes in them). Hermione LOVES the willow balls as well, but not for chewing. She picks them up with her teeth and throws them so she was chase them or tosses them with her front paws. Really, Hermione would play with anything you put in front of her (if she doesn’t eat it first, she’ll eat ANYTHING if she sees me eating it too). I can’t find a sutiable replacement for the wicker balls other than baskets they like to hide under and those are usually destroyed in days.

That all sounds great, I love diy stuff.

But I do think I saw Oak on a list of toxic woods somewhere

I know that apple, pear, willow, and citrus are safe, even when fresh.

Fruit trees where the fruit has pits; the wood from those is toxic when fresh. Supposedly there needs to be a dryout period and then the wood is safe.

Apple branches however are good right off the tree that’s how my bunny likes them.

They don’t list Oak in the safe list at the bottom (only that it can be medicinal), and I have seen it on a list as toxic: https://www.thespruce.com/safe-woods-and-plants-for-rabbits-1239351

Personally I wouldn’t risk it… And yes, not all fruit is safe (peach, apricot, cherry, plum are all toxic), but apple/pear and citrus are safe.

DanaNM is right, oak is toxic to rabbits, both leaves and the bark. However the effects are not always immediate, but the damage is long term-so it isnt noticed now, but will be seen in the future. Eventually it causes liver failure. It’s the same in horses. I’d advise removing anything oak.

Soft woods are generally the best, especially sweet woods-things that bare fruit such as blackberry and raspberry bushes are really popular with mine (some people advice against blackberry cause the thorns can cause some issues, but if you use the younger stems they are easier) also grape vines are very popular. Ash trees are seemingly fun to chew as well (judging by the fact I planted a about 50 and wild rabbits ate half of the saplings !)
Apple is a slightly harder wood, and not as sweet so is sometimes ignored as a chew toy.

Yes, grape vines are VERY popular with mine. All of them love them, especially Fred. Be sure to rinse them unless you buy them organic though, because they can have a lot of pesticides.

What a great litter box idea! Thanks for sharing – I might do that when my bun needs a second box around the apartment.

Haha, i have to say, I was a little surprised you were using cardboard! I thought there was a plastic tray inside it….