First off, any "chubby" ones are most likely pregnant females.

They do not require any heat, they are a cool weather snake that prefers it to be right around 60 or so.

I have kept and bred quite a few, never used any heat.

what you chose to do is up to you, but by collecting pregnant females the population reduction is compounded tenfold.

2-3 can be kept comfortably in a ten gallon tank.

what you need is simply a water bowl and a place to hide.

chose your substrate wisely, use the big chunks of bark if you are going to feed in the cage, worms and slugs are sticky and fine substrate like coconut fiber or aspen will stick to the food.