Guinea pigs clicking teeth when introduced: Are they fighting?

Thanks for reaching out. Not all animals get along. The biggest question is are they fighting or trying to establish hierarchy. Separate then for now and introduce them slowly in a neutral territory. Neutering them to lower testosterone might help. You should contact the store, to see if they can help also.

In any grouping of animals you will have some sort of dominance hierarchy. Problems arise when one is so dominant that it won’t allow the other to eat enough, or when they start to injure the others then I worry that it isn’t a safe situation. If you have noticed scabs or wounds on them you may need to consider separating them when they are not being supervised. The same situation will apply when you add in a third. The dynamic will shift with 3. Either it will be easier and they will get along better, or one will clearly be the submissive and get picked on too much. Monitor closely and make decisions to make sure they are all safe. Best of luck and have fun with your pigs! Thank you for using Pet Coach.

Based on the behavior you are describing I would not recommend housing these pigs together right now. The older pig is exhibiting some signs of dominance which can quickly turn to aggression. I would recommend allowing them to interact and play with each other under your supervision. If you ever notice that these behaviors stop then you can try housing them together. I hope this helps. Thanks for using Petco Pet Education Center, formerly Petcoach. Best of luck.

It may be excitement or it could be aggression. If you plan on physically introducing them, wait until Sebastian does not make the noises anymore and then put them together for ever increasing periods of time. If there is any aggression, separate them immediately.

Congrats on all three guinea pigs! Squeaking can be a sign of many things. Here is an article to read regarding happy squeaking: https://www.petcoach.co/article/how-to-know-your-guinea-pig-is-happy/ Here is also a great article about caring for guinea pigs: https://www.petcoach.co/article/the-best-way-to-care-for-and-feed-your-guinea-pig/ If the males get along, you may consider housing them together (do not put males and females together unless you intend to breed and then make sure to do your homework first). Guinea pigs do prefer company (as long as they get along) and if they don't have other guinea pigs to hang out with, the humans must make time every day for interaction. I hope this helps and please feel free to post any additional questions.

Anything other than aggression or fleeing is a "good thing". Continue to allow them to be together for longer and longer periods of time. Introduce toys or treats to make sure there will be no resource protection or food aggression.

Thanks for reaching out about Cookie and including photos. A veterinary visit is recommended to assess and provide a diagnostic/treatment plan. This could be due to bite wounds but also possible dental disease. As guinea pigs mature, they might become more territorial and competitive. Is a larger cage possible, providing multiple feeding and water stations, more hiding places. Not all individuals get along, and might need to be separated. Good luck.