From an engineering point of view their control loop must be much faster. Things that fly need much tighter loops than we do that lumber about on the ground.

Watch a bird come in fast and then land on a narrow twig.

Bird neurons are roughly half the length of mammal neurons. This means you can pack in around 8x more neurons in a given volume.

Yeah, you can just (try to) watch them move their heads around looking at things. They move faster than the human eye.