Dd2 has two rats that are now just over a year old. The hooded dumbo rat (Nibbler) has started making an almost constant chattering/chirruping noise. He shows no signs of illness, is active and eating/drinking but I thought rats were silent creatures and the other rat does not make this noise at all. Is he okay or should I get him checked out?
Definitely get them checked out, rats should be silent most of the time. Constant noise can be a sign of a respiratory infection (though the chattering could be bruxing which they usually do when happy but can do it when stressed or ill too). Make sure that they are a vet who has experience with rodents/small animals too as a lot of 'normal' vets aren't the best with rats!