Perhaps the biggest problem researchers face in complying with the new regulations is measuring the emotional well-being of animals, which can't describe their feelings. We can't define happiness for people. One way is to measure physiological responses. At the center, tiny devices are placed under the skin of animals to monitor their heart rates and body temperature. These devices gauge, among other things, the effect of different people coming into the room.
Early indications are that the animals prefer the company of janitors over veterinarians.
For now, researchers will try just about anything to cheer up their test animals. The buddy system works wonders at the Wisconsin Regional Primate Research Center in Madison, where placing an infant monkey with an older one seems to inhibit aggression. When scientists need the animals, a companion comes along. Perhaps not surprisingly those in captivity would rather work for their food than accept government handouts. Food puzzles, in which a peanut has to be pushed through a maze, are popular, too.