Here's why:
* Natural instincts: Guinea pigs are prey animals and have strong instincts to defend their territory.
* Hormones: Male guinea pigs produce testosterone, which makes them more aggressive.
* Competition for mates: If there are female guinea pigs present, males will compete for their attention, which can lead to fights.
* Lack of space: Even if there are no females, males will fight if they feel crowded or lack enough space to establish their own territory.
How to avoid fights:
* Introduce them slowly: Never put two males together directly. Instead, introduce them gradually by allowing them to sniff each other under the cage door or in a neutral space.
* Provide plenty of space: Make sure the cage is large enough for both males to have their own space and resources.
* Neuter them: Neutering can reduce testosterone levels and make males less aggressive.
* Separate them if necessary: If fighting occurs, separate the males immediately and consult with a veterinarian.
Important note: Even if the males appear to be getting along, it's always possible for fights to break out suddenly. Therefore, it's important to monitor them closely and be prepared to separate them if needed.