|MadSci Network: Zoology|
Dear Eric, My cats do this too. It is very strange! According to the world's cat experts, the answer to your question is either "we don't have a clue" or "it is related to the killing instincts of the cat." I would suggest, therefore, that you accept that the behavior _might_ be related to the behaviors cats perform when they kill their prey, but that we really don't know for sure. To be more specific about how that clicking noise you hear relates to killing prey, I'll tell you what Desmond Morris says in his book _Catwatching_. He explains that when a cat kills any prey item, it opens and closes its jaws around the animal's neck very rapidly. This opening-and-closing movement is the best way for the cat to slide its canines inbetween the prey's vertebrae, killing it quickly and risking less injury to the cat itself. Morris suggests the reason we hear our cats make that noise while watching birds through the window is because they are so excited about seeing their prey that they are making the killing bite in advance. It's the same idea as when our mouths start to water in anticipation of a good dinner just because we smell the food. The main problem I see with this theory is that it is extremely disadvantageous for a predator to make any noise while hunting. It might scare off the prey, right? So do cats only make their instinctive, advance killing bite when they are "hunting" birds through the window? If so, it would seem that Morris' explanation does not take this into account, or maybe is incorrect. I'm sorry I can't give you a clear-cut "this-is-the-way-it-is" answer to your interesting question. Surprisingly, there are lots and lots of things we don't know about domestic animals like cats and really common wild animals like opossums and skunks. If you're interested in these sorts of questions, I would suggest reading books like Desmond Morris' _Catwatching_, and thinking about the answers he gives to common cat questions. Do they make sense to you when you think about how your cats behave? You could be heading towards a career in animal behavior, and the possibility of answering some of those questions yourself! Thanks for your question, Andrea Bixler
Try the links in the MadSci Library for more information on Zoology.