Sleep regression is a phenomenon where horses are able to wake up when they are hungry.
When they do, they will spend more time in the open pasture than when they were sleeping, researchers say.
Sleep regression occurs when horses, which typically spend most of their time in closed pens, spend more of their sleep in the grass than they would when they slept.
Researchers are now trying to figure out why.
“It’s not just a sleep issue,” said Dr. David P. Dabrowski, a veterinarian at the Washington State Department of Fish and Wildlife.
“I think we have to look at the physiology of sleep to understand why this happens.”
Dr. Dabbrowski has been studying sleep and sleep regression in horses for years.
He is a member of a research team led by Dr. James F. Johnson, an assistant professor of animal behavior at the University of California, Santa Barbara, who is working with researchers at the Oregon State University, and the University at Buffalo, to figure it out.
Dr. Johnson said that the researchers have noticed that the horses who are most likely to have sleep regression are the ones who are getting the most feed.
In fact, they tend to be those who are the least active in their social groups. Dr