There are a few reasons why guinea pigs might chatter their teeth.
One reason could be because they’re excited or happy.
Guinea pigs have been known to make a chattering noise when they’re being playful or when they see their favorite person.
Another reason why guinea pigs might chatter their teeth is because they’re trying to communicate something.
If a guinea pig is chattering their teeth and also making other noises they might be trying to tell you that they’re hungry or that they need more hay.
If your guinea pig starts chattering their teeth it’s important to observe their body language and see if you can figure out what they’re trying to tell you.
If they seem happy and playful then there’s no need to worry.
But if they seem distressed or like they’re trying to communicate something then you should take them to the vet to make sure there’s no underlying health problem.