I've never had any problems with housing hatchlings together. Depending on how young they are, I'm sure you could keep them in the 10 gallon for a little while. Normally, if you have more than one hatchling together, they seem to help each other with security. Everytime I check on my hatchlings, I can be sure that they are all coiled into one ball together. They're too young to breed, and most have been together since they were hatched, so they're normally not aggressive with each other. I seperate them once they're about 6 months old or so. Any "trouble makers" are sperated earlier of course. It does help save space, and if I do need to seperate them, I normally pick up a little 5 gallon plastic cage (the ones with the handles) until they're big enough for a ten gallon. They do sell lights and small heating pads made especially for them, so they work pretty good for small snakes. If they are housed alone, I don't like to put my juvies into large tanks. It may just be me, but in a smaller space, hatchlings seem to be a little less elusive. I don't want them to feel "lost" in a huge 10 gallon (well, huge to them) as a hatchling, so until they NEED a bigger enclosure, they stay in a smaller one. Some snakes (especially burmese pythons) can get very stressed if their enclosure is too big. It normally makes them very insecure because the "vastness" of their surroundings is so big. Thats just how I do it though. It seems to work. My yearlings normally go into ten or 15 gallon tanks until they get over 2 to 2 1/2 feet. All of my adults (unless they are unusually large) go into 20 gallon long tanks by themselves and they all do fine. Once breeding season rolls around, I have a handful of 50 gallons that I use so both the male and female have plenty of room.