The Clinical Center at the National Institutes of Health in Bethesda, Md. National Institutes of Health hide caption

itoggle caption National Institutes of Health

Two chimps groom each other at the Save the Chimps facility in Florida. The National Institutes of Health owns about 360 chimpanzees that aren't yet retired and that are living at research facilities; new guidelines say most of its chimps should be retired. Save the Chimps hide caption

itoggle caption Save the Chimps