Does anyone else have the problem of their dog sitting at the rat cage crying because he wants the toys that the rat has?

I was just curious to see what toys people give their rats to play with? I give mine swinging bird perches with bells on them, parrot toys with mirrors on them..treat balls (the kind used for ferrets, you put the treats in the balls, and they roll them to get the treats out) But I also use the...

I got this toy for my rats. Its a bunch of wooden peices with a walnut inside. Is it ok for them to eat a whole walnut?