Raising rats is work x time, smell, and frustration.

It does make it worthwhile money wise. On average, each rat I produce as a feeder costs me .43 cents.

But, on the other hand I have to agree completely with Jo. If you can, buy from a someone with a good rat colony. Avoid high white rats, and make sure they are healthy, young (just weaned is preferrable), and free of parasites.

Rats don't do well with high temps. I have a significant slowing down in production during the summer. Here it gets well into high 80's 90's, and there is the risk of heat stroke/ exposure. When it gets that hot, I make sure I have a high velocity fan running on the rats, sometimes I will mist them down if it's really hot.

Rats prefer to be kept in temps that you and I like. Between 65-75 if possible. They can tolerate lower temps, but be careful about high temps. It's easy to lose rats that way.