Darlene Foti, age 11, of Rochester, New York, for her question:

Do insects have brains and hearts?

The parts of an insect must fit into a very small package. He has a tiny brain and a tiny heart. But as you would expect, they are quite simplified. His head has at least two eyes, assorted mouth parts and two antennae. This does not leave much room for a brain. Actually it is not much more than a bulge in two major nerves. It connects with the rest of the nervous system throughout the insect's body.

The tiny heart is not much more than a glorified blood vessel. It lies more or less where the insect's spine would be, if he had one, and pumps blood throughout his body. The circulation is very slow because the blood vessels are not connected in an unbroken circuit. A main vessel from the heart opens into the head. From there the blood oozes through spaces to the abdomen, where it absorbs food. It seeps through more holes and spaces to deliver nourishment to various cells, then oozes its way back to the little pulsing heart.