Rusty Grabrielson, age 11, of Lexington, N.C., for his question:
DOES THE THOUSAND LEGGER REALLY HAVE 1,000 LEGS?
This skinny little creature is only an inch or so long, but it might take most of the day to count his legs, one by one. What's more, he has quite a few cousins that come in assorted sizes. The larger types have more legs than the smaller types. Some types have only 80 legs, others have several hundred, but not one of them has as many as a thousand legs.
The name centipede means a hundred legs. The name millipede means a thousand legs, which is why some people call him a thousand legger. These small creatures are related to each other and all of them have long bodies with segments, somewhat like strings of crusty little beads.
A millipede has a pair of rather stubby antennas. A centipede's feelers are like long whiskers. All of them have tough meat eating jaws and skinny little legs with many joints and scratchy feet. A millipede has two pairs of legs attached to each segment of his body. A centipede has only one pair of legs on each segment.
The easy way to count a millipede's legs is to count the segments and multiply by four. For centipedes, we count the segments and multiply by two. One would expect all the centipedes to have 50 segments with 100 legs. And surely the millipede should have 1,000 legs attached to 250 segments. But this is not necessarily so.
The small type centipedes are about one inch long and they have only 24 legs. Larger types have 30 and some have 100. Some centipedes of the tropics are 10 inches long and have as many as 346 legs.
A small type millipede may have only 80 legs. Larger types have 100, 200 or 300. The largest millipede has about 400 legs which is a lot less than a thousand. There are hundreds of these small cousins and most of them live in the damp, shady woods. They detest daylight and come out at night to feed on slugs and grubs.
Sometimes these leggy midgets sneak indoors and hide in the kitchen, hoping for scraps of food. You may wonder how they manage to scuttle along without treading on their own toes. But this is no problem. All the legs march along together, keeping in step. They never trip, even when scuttling along at high speed.