pigs.

Pigs are among the most cognitively complex domesticated animals alive. They have been shown to play video games using joysticks, understanding the relationship between their actions and on-screen outcomes — a task that requires abstract thinking beyond what most animals can demonstrate.

Pigs demonstrate empathy — showing measurable emotional responses to the distress of other pigs even when they themselves are not threatened. They have long-term memory for specific individuals and experiences, and they form close friendships within their social groups that influence their stress levels and behavior.

Pigs are also among the cleanest domesticated animals when given appropriate space — they never defecate near where they sleep or eat.