Do you have to cool them down? The answer is no they will breed and make eggs without cooling. Does it help? You will get different opinions here but I will say yes. I use just the ambient temp for cooling down. It naturally gets cooler in the winter here in northern WI and I use that. Some put their heat tape on timers. There are different ways and different thoughts on it. If you are only breeding a handful of girls then there probably would be no need. If you are breeding a bunch of girls I think it helps getting them more in sync. I might have a boy that breeds 8-10 girls. I need him to breed like a maniac for about 4 months and then shut him down. If my girls development is spread out over say 8 months then I can't breed them all with that boy. I also had one year I didn't really cool them and ended up with a lot of slugs. Was it bad luck or the temps I don't know. I do know when I cool though I get very few slugs.