I have a few quick questions I'm hoping someone can give me advice on.

First:
Is there a way to help insulate a single tub, winter is coming and the temps in the tank are going to drop that, I wanna try to keep it as warm as I can for my little guy.

Second:
Right now I feed him F/T hopper mice every 5-7 days, I want to switch to rat pups, how much bigger are the pups than the hoppers?

Third:
Where do you guys purchase your rats/mice, online or at a pet store?

Thanks for all your help guys.