Whenever I see a mostly feral character in a movie I imagine them sleeping in a pet bed, and GOTG 2 has more footage of Rocket running on all fours. So I imagine Peter picking him up a round pet bed and Rocket curling up to sleep - after Peter lies and claims it's a bed for small feral aliens. No to be mean and laugh behind Rocket's back but because they're friends and he thinks Rocket will be more comfortable curled up.