it usually looks like somthing good to eat
Because they're dogs and dogs like to chase things.
Dogs will chase things that run, that is instinct.
The same reason they chase cats and squirrels and mice. Dogs are predators. Predators chase things to kill and eat.
Dogs like to chase things, eat, snuggle, and play with YOU.
Most dogs naturally chase after things.
Because dogs have something called 'prey drive', or in domesticated dogs, 'ball drive', an instinctual behaviour instilled in wild dogs to motivate them to catch their prey. because there's no need for prey drive any more (assuming you're feeding them...) they get the urge to chase various things, light happens to be a challenge for them to chase (just like balls, cars and even shadows or people sometimes).
Many dogs will. You can train them not to but most dogs instinct is to chase critters like squirrels.
because they are dogs they roll around in mud and chase things to a place where it probably smells
Dogs chasing cats is a stereotype, but they will chase cats and other things if they are excited! It also depends on territorial issues as well. If the cat had already claimed the territory, then the dog may chase it to try and get that territory, or if the dog had claimed it first, then it may chase the cat to get it off said territory.
Most dogs will kill chickens if they are not trained not to chase and kill things.
no, dogs just chase just bout anything that moves
Both. Depending on the dog and cat, dogs can chase cats, but some feisty or territorial cats are more than capable in chasing away a dog.