Aggressiveness
From Cantr II Wiki
Aggressiveness determines how likely an animal is to attack.
A random percentage is drawn from a normal distribution with a mean of "Aggressiveness / 10" and a standard deviation of +/- 0.3% This is then divided by 4 and if it exceeds a random value drawn from a uniform 0 to 100 scale then the animal attacks.
Animals with an aggressiveness of zero never attack.