From PinataIsland.info, the Viva Piñata wiki
Sour pinatas and ruffians aren't the only cause of trouble in your garden. Each pinata has its own little quirks, and doesn't always get along well with others. Some pinatas simply dislike another particular species. Each species has its own unique attack that comes into play. For example Fizzlybears will spit puzzle pieces when they get angry. Pinatas may also fight when they are repeatedly poked using a spade and will fight the pinata closest to them. Pinatas will have red eyes surrounded by red steam when wanting to fight.
Some solutions to help resolve these quarrels include the following:
- Taming a sour Bonboon to help break up fights
- Building a habitat in a different part of the garden to keep adversaries separated by distance.
- Watering pinatas with red eyes from a fight will stop them from starting new ones