From time to time, you may notice that your gerbils are grooming each other. They’ll sit on top of one another and comb through one another’s hair, searching for insects and smoothing out tangles. This behaviour means that they’re getting on well - it’s one of the signs people look out for when introducing gerbils for the first time. It shows that the gerbils trust each other (for now) and that they are willing to help each other keep clean.
Gerbils will often groom each other - sometimes this will be to reinforce their social bonds
One of the reasons gerbils groom each other, as well as a bonding exercise, is that they sometimes need some help with the hard-to-reach places. This is one of the many reasons that gerbils should not be kept on their own.