When your dog sees that little wiggly bead of light from a laser pointer, nothing matters to him more than catching it. Unfortunately, there’s nothing there to ‘catch’, since it’s just an ungraspable bundle of light. And, it turns out, the lack of closure your dog experiences from endlessly trying to catch it may actually be screwing with this head.

Dogs instinctively chase those bright red laser dots simply because they’re moving; stimulating their natural prey drive. The laser beam’s incessant moving taps into this prey drive and the dog can’t help himself – he has to chase it, according to Nicholas Dodman, a professor of animal behavior at Tufts University’s Cummings School of Veterinary Medicine.

But, according to Fox News:

…should you really be stimulating your dog’s prey drive when it won’t ever lead to triumph — the catching of light? Probably not such a good idea. “They can get so wound up and driven with prey drive that once they start chasing the light they can’t stop. It becomes a behavior problem,” Dodman said. “I’ve seen light chasing as a pathology where they will just constantly chase around a light or shadow and pounce upon it. They just spend their whole lives wishing and waiting.”

Never getting a reward for their vigilance “makes dogs loopy,” he explained. Along the same lines, trainers of bomb- and drug-sniffing dogs have found that their dogs become psychologically disturbed if they never find bombs or drugs, so they must occasionally be taken on dummy missions.

If your dog loves to chase, Dodman recommends using more tangible toys that he can actually catch. Or if you must use a laser toy, one solution is to hide treats around the room and occasionally land the laser light on the treat to surprise your pup.