We have been at a hamster show today and there was a litter of dwarfs with mum in a tank. Now these little guys could only be described as buzzing! They most definitly sounded like insects! It is not uncommon for hammies especially young ones to chirp and squeak. Check the ear and look for any discharge, lumps, bumps or red looking skin or scabs which could be painful and causing him to make the noise. If you think there is any cause for concern a trip to the vet to have it checked out may be in order. Otherwise keep a close eye on him and maybe he is just a chatty ham