Why does my guinea pig vibrate and make noise when I pet it?

Yes, this is normal. Purring is typically associated with being happy and content, and Pennie may enjoy being picked up and held by you. No, you cannot stop it and it's a good thing, so enjoy that she likes being picked up by you! :-)

I think is perfectly normal for her to do that (vocalizing may be an actual good sign!) and, by your description of what you are doing, I think you are not doing anything wrong at all! Please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further.

Guinea pigs aren't always naturally tame as they are a prey species so can be skittish/fearful at first. I would recommend reading this article on how to tame your guinea pig to help develop a bond between you and your pig to allow him to be more relaxed around you: https://www.allguineapig.com/taming-your-guinea-pig/

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.

I think what you are describing is “popcorning” which is a normal behavior guinea pigs do when they are excited. They will bounce or pop up and down quickly. It sounds like Hershey is just having fun and enjoying himself!

Excessive vocalization can sometimes indicate pain or illness, so following up with your vet to see if Toffee's infection has cleared is best. It may be that she is also feeling a bit better and is more active/excited to see you and thus vocalizing. Taking into account other things such as her activity levels, how much she's eating and drinking, how playful she is, etc can help give you a better indication of her health and pain levels than just squeaking alone.

It's possible Sally could be a bit constipated, ill, or have irritation/infection that is causing some swelling or discomfort. If she can't go potty at all, there is swelling/oozing of debris, or she seems in distress, it is a good idea to bring her to your vet for an exam. Otherwise, keeping everything clean and dry and making sure she is eating and drinking may help her stay comfortable.