Timothy hay is a grass that is basically dried Timothy grass. It is very popular with rodents such as rabbits, guinea pigs and chinchillas who use it to grind ther teeth on.
So can gerbils eat Timothy hay?
Yes they can but only a handful once a week at the most. Any more and they will get diarrhea.
Timothy hay can be purchased from most pet stores but there are better foods for gerbils that can be bought especially for them.
If you have a pet such as rabbit or a guinea pig who love Timothy hay, your Gerbil may appreciate having a few stalks as well.