Asian flatworm invades North America, may decimate earthworm population.Bipalium kewense is the scientific name of the hammerheadflatworm or land planarian that somewhat resembles a hammerhead shark.Hammerhead worms are not poisonous, they do not bite, and they cannotharm people or pets. However, these worms can be disastrous to gardenersand their crops because the hammerhead's favorite food is thegardener's best friend - earthworms. Ordinary earthworms are beneficialto gardens because they aerate and fertilize the soil. A severeinfestation of hammerhead worms can quickly decimate a garden'searthworm population. Hammerhead worms can be as long as 20 inches,but most are about one inch long. They secrete thick mucus from theunderside of their bodies that leaves a trail behind them as theytravel. They may or may not have stripes and are usually shades ofbrown, black, gray, or orange. Hammerhead worms will regenerate newworms when cut into pieces, so it is not a good idea to try to kill aworm by squishing or smashing because you will only create more worms.