Cast aside all fantasies of your house cat frolicking through flower-filled fields in the afternoon sun. When kitty scratches at the door begging to go outside, it's the killing hour.

USA Today reports that a study of outdoor feline behavior found that cats kill far more prey than previously believed. Research compiled by the University of Georgia found that 30 percent of roaming house cats kill an average of two animals per week.

"The previous estimates were probably too conservative because they didn't include the animals that cats ate or left behind," University of Georgia researcher Kerrie Anne Loyd says.

Teaming up with National Geographic (creators of the Crittercam) for the study, 60 volunteers attached the so-called kittycams to breakaway collars that were placed around the necks of the cats. Each day, the previous evening's activities were downloaded and sent to the university research team.

The university study found that cats ate about 30 percent of their kills, brought home another 25 percent and left 49 percent of their prey to simply decay.

So what are cats killing?

Lizards, snakes and frogs (41 percent); chipmunks and vols (25 percent); insects and worms (20 percent) and, of course, birds (12 percent).

And while birds made up the smallest percentage of kills, some conservationists say the nation's 74 million house cats are to blame for dwindling bird populations.

"Cat predation is one of the reasons why one in three American birds species are in decline," George Fenwick, president of American Bird Conservancy, tells the paper.

But the study also found that cats pose just as much a risk to themselves as they do other creatures, with 45 percent crossing roadways, 25 percent eating and drinking items found outdoors and 20 percent exploring storm drains.