Cat EEGs

Scientists use a sophisticated device called an electroencephalograph (EEG) to monitor the activity of the human brain and the brains of some animals as well. By using the EEG, we’ve learned a lot about cats’ sleep habits, as shown by the wavy line displayed on the EEG.

We have learned that a cat typically sleeps lightly for about thirty minutes, and then goes into a deeper sleep, called REM sleep. Most often, though, cats aren’t sleeping deeply. Of their daily dose of about sixteen hours of sleep, probably 70 percent of it is light sleep—the “catnap” that is their trademark.