Anyone who's seen a cat outdoors chomping away at the lawn like a billy goat knows that cats like to eat grass.

We don't know for sure why cats eat grass, but we have some theories. Grass can help cats spit out the hairballs that have formed in their stomach from the hairs they've swallowed while grooming themselves. Some scientists also believe cats get certain vitamins from eating grass.

If you have an indoor/outdoor cat, don't use weed killer and other poisons. In fact, it's best not to use these substances even if you don't have a cat, since it's likely that some of your neighbors have cats that may pass through your yard on their daily adventures.

Cats who live indoors won't have much chance to nibble on grass, but you can buy "cat grass" or "cat salad" for them in most pet stores and even in some grocery stores. Your cat will enjoy nibbling on these green shoots of grass, will be less inclined to chew on your houseplants, and will get the health benefits this instinctive but curious habit provides.