Is animal companionship a form of therapy? A patient (right) and therapist (left) feed ring-tailed lemurs at Serengeti Park near Hodenhagen, Germany, as part of a monthly program called “Psychiatric Animal Days.” The program is based on the assumption that animals have a calming and therapeutic effect on people. As many as 400 kinds of therapies are currently used for psychological problems. An experimental design is needed to determine whether this or any other form of treatment causes clients to improve.