Well, they get along fine now. Actually, they've been sleeping next to each other, etc. since I got them at about 4 weeks old. So I'm assuming that if they are boys, they are used to each other by now. I actually had them one time in two large critter keepers right next to each other and the whole time they sat there looking at each other through the plastic. When we took the lid off one, Piper ran over and crawled in with Wilson and they went to sleep. It's interesting because I didn't think cresties were that into having other cresties around or companionship like some other animals are.