The hostility between the two is palpable, but the macro made a classical mistake: Never ever put your face too close to a micro. With a swift kick to the nose, the chase starts. Course, as a cartoon, the same animation is used with a changing background. Ah, old cartoons.
The macro finally gets close enough to launch himself into the air and effectively squash the micro underneath him. Crushing is what macros do best, but a common error they make is that most of the body parts they use to squash micros are also the most vulnerable. So, with a wide target area like the macro's white fluffy stomach, all it takes for a micro to escape is to reach out and give him a good tickle.