Keeping Ratties busy?

I'm hoping to pick your brains, fellow ratter friends:

My rattie needs more to do. I've bought puzzles and games, he figures them out in 15 minutes or less.

He needs more to do. Both for his mental and physical health. I've thought about agility courses, but what about the other days/times?

He has ZERO interest in the dog park (with friends or alone) and will play ball for all of three throws then he loses interest. We tried daycare for a while; he got bored after a week, which sucked because I bought a 30 day package deal. 😐

He loves walks, but doesn't understand that the boring stuff we do all day is what pays for him to have a good life.

This dude is BORED, and as you know - a bored rattie is a sad (and sometimes naughty) rattie. Even though he comes to work with me, he still needs his own work to do.

So, questions:

1.) What toys do you guys have for your pups? He obliterates anything with stuffing. Even the alleged "tuff toys."

2.) What do you do to keep your pup's brain busy?

3.) What do you do to keep your pup's body busy?

Thanks!