Just like us humans, I guess.

Always wanting what we don't have, regardless of how much we
do have.
Gracie Ruth will steal Yogi's toy and jump up on the couch with it. Yogi can't get up on the couch yet, so she knows she's safe from him stealing it back. He'll give up barking at her and go get another out of the toy box. And of course, that is the one she wants now. She'll jump down, steal it from him and jump back up on the couch. Eventually she ends up with nearly all the toys on the couch. Yogi has figured this out and will now simply lay
on the toys
in the toy box, thus claiming them all for himself.
It is hysterical to watch and listen to them play/fight with each other. Who'd of thought 2 such small dogs could make so much noise!