cats have been domesticated for hundreds of years, and they adapt very well to human company and lifestyle. when handled
correctly and socialized from an early age, a kitten makes a very good pet.
feral cats however, with little contact to humans, are not tame at all. they show
aggressive behaviour fueled by fear and the unknown. it is also part of their self-defense mechanism.
pet cats can turn aggressive as well though. this may be down to bad treatment when they where little, early weaning or seperation from the mother, lack of handling and social contact with humans, illness or injury or instinctive behaviour.
if your cat suddenly reacts aggressive on touch, check if it is injured or ill in any way
in case you have adopted a cat with an unknown background and aggressive behaviour occurs, give it time and don't force your love and affection on it. it will come forward in its own pace, be patient and calm. this can take a while, don't give up to soon
don't tickle a cats tummy just for fun unless you know the cat very well, otherwise you might be in for scratches and bites