Forget that old squabble about which is smarter, dogs or cats. They're both smart. Look at them, lying there in the only patches of sunshine in the house, lazily hogging the beams as the sun shifts. It's almost as if they were addicted. "Well, of course we are," they would say if they could talk. Lying in the sun just feels so good. And you humans needed a scientific study to tell you that? Apparently we did. A report published in the July issue of the Journal of the American Academy of Dermatology (and causing a lot of nervous scoffing by tanning-salon proprietors) confirms what dogs and cats already knew.

Soaking up the sun isn't mainly about acquiring a bronze glow for the beach, although that's a bonus for hairless, pale-skinned humans. It's about getting an all-around mood boost -- and it's arguably addictive. Which means that tanning-bed devotees might find it much harder than they thought to resist those warnings by dermatologists about the dangers of overexposure to ultraviolet light.

Researchers in North Carolina set up a cunning experiment. Fourteen people were invited to tan twice a week, splitting the time between a bed that emitted UV light and one that didn't, though they looked identical. The subjects' moods were measured before and after each session and were found to be noticeably better after they had used the UV beds. The subjects were then invited back for an optional weekly third session and told they could choose between the beds. Twelve of the 14 chose to come back and, of those, 11 picked the UV bed every time.