Attempting to understand your guinea pig's body language can be a baffling and confusing experience. After all, there really isn't much of a correlation between rodent and human nonverbal communication, if any. Licking and nibbling behaviors in guinea pigs can mean a variety of different things, from affection to fear.
Guinea pigs avidly groom themselves, but it also sometimes extends over to you, too. If you notice your wee pet enthusiastically licking your hand, the RSPCA indicates that it may mean that he's actually attempting to groom you to cleanliness -- a rather kindly guinea pig gesture.
Licking Up Salt
On the other hand, a guinea pig licking on your hand can also mean something totally different. By licking on your hand, your pet may actually be trying to lap up the salty taste of your skin. Essentially, your guinea pig is using you for a quick snack -- nothing more, nothing less.
Fear or Discomfort
A guinea pig may nibble on your hand as a reaction to fear or uncertainty. By nibbling on you, he is basically conveying the message that something is wrong. Perhaps he doesn't like the way that you are stroking his back, and wants you to stop -- pronto. He might have a "call of nature" and need to use the potty ASAP. Maybe the sound of street traffic coming from outside is causing him to feel rather unsettled and nervous. Nibbling also could signify physical pain. If your guinea pig is particularly anxious or scared, that subtle nibble could escalate into something a little bit more painful -- think a bite. Be very careful if your pet nibbles onto your hand, and heed the warning. Put him carefully back down for the time being -- that's what he wants.
Smell of Food
If you just recently came into contact with something tasty in your kitchen, your guinea may detect the smell and confuse your hand with something edible -- uh oh. To avoid your guinea pig ever snacking on your hand, always thoroughly wash your hands before partaking in a petting session with your fluffy cutie.
The licking of your hand could also point to sheer joy. Your guinea pig is feeling loving toward you, and just content in general -- aww. Along with the licking, you may notice other jovial behaviors such as squealing.
George Doyle & Ciaran Griffin/Stockbyte/Getty Images