Coriena...
Check your gerbil's lower teeth. If they have become too long, they could be
rubbing against and irritating (hurting) the upper part of the mouth. Your
gerbil may be trying to alleviate possible discomfort by scratching.
We have seen this in our gerbils on occasion. If this is the case, best to
see a vet.
The vet can trim the teeth, provide an antibiotic if there is a secondary
infection and suggest a topical solution for the snout. In the past we have
used a 50% solution of water and Betadine solution as a topical application...
as per our vet's advice.
Nevertheless, you may wish to consult a vet anyway....
Warmest regards...
Pat
