We have two cats who continually compete to see who can sit closer to me.

I slowed this down because the cat’s reaction looks completely instantaneous.

• At frame 133, t=0 ms, the first smack hits the calico cat in the head while she’s completely asleep.
• At t=67 ms, the second smack glances off her neck, because she’s already moving to react.
• At t=167 ms, the third smack completely whiffs, because she’s already got her feet under her, claws out, assessed the direction of the threat, and she’s moving backwards.
• At t=233 ms, she jumps. By the next frame she’s already flying through the air away from the threat.

Most humans, if you tell them to hit a button when a light flashes, can’t do it in that length of time, even if they’re awake and alert and watching for it with their hand on the button.