[header] How to introduce two guinea pigs to each other [title] Determine the sex of your guinea pigs. [step] Sex makes a big deal when it comes to how guinea pigs interact with one another. Before you introduce them, you must determine their sex. 
Pet shop employees often make mistakes, and if you're buying a guinea pig from a pet store the chance of error is even higher. [substeps] You should examine your guinea pig on the floor or a very low table.