Q: I have two female gerbils, and I had them in a split cage for two weeks before I put them together. They did great together for almost two weeks, but when I got home today one was bleeding from her back leg and the other from her face. I put peroxide on the spots and split the cage again. Do you know what would make the gerbils start fighting, and will I be able to put them together in the future?
A: I’m sorry to hear that your gerbils are fighting. This is too bad; usually once you get a gerbil pair together they are friends for life.
Sometimes a shortage of food or water can cause gerbils to fight. Make sure these two always have plenty of both.
Sometimes the tank setup can get gerbils territorial. You could try them together again in a simple, yet stimulating, arrangement. For example, a 10 gallon tank with a mesh wheel hanging from the top, a box in one corner to sleep in, a dust bath or sand box (remove this and wash it after a few hours of playtime), deep litter and a paper towel tube. Keep away from complicated setups with levels and plastic tubes, because the gerbils might set up separate territories in these.
That said, once two gerbils draw blood it can be difficult or impossible to get them together. Watch these two carefully; if they fight again or show other signs of aggression, keep them separated permanently. If this occurs, place the two cages close enough together so that they can see, smell and hear each other. The gerbils will appreciate the company of having another gerbil nearby, even if they do not get along well enough to live together.