When a human sleeps, they toss and turn. This tossing and turning usually manifests itself as the upper part of the body rotating back and forth on the top of the mattress, and the lower part of the body translating back and forth across the bottom of the mattress.

This motion results in the creation of a critical zone about 3/4 of the way from the top of the mattress. All cats are aware of the location of this critical zone. In fact, that is where they lie down to maximize interfering with your sleep. The exact location of this critical zone varies depending on the height of the human, but cats have an innate ability to figure out the location of this zone based on the height of their human and plunk themselves down there. Cat don't even have to measure their human with a measuring instrument (have you ever seen a cat with a tape measure trying to measure a human?). They merely eyeball their human, make a judgement call about how tall their human is, and plunk themselves down on the mattress accordingly.

Copyright © Aaron Hirshberg
March 17, 2000