Mike Merritt, age 14, of Solana Beach, Calif., for his question:

DO INSECTS HAVE LUNGS?

Insect statistics are almost mind boggling. There are more than 700,000 different species living in every part of the world. There are more than 3 billion people in the world, but we can often find more than 3 billion. insects in a single sauare mile.

'Insects all have six legs. They don't have lungs, but they have a most interesting breathing apparatus. They take air in and through a number of airholes (called spiracles) arranged in pairs and extending down the insect's thorax and abdomen. The airholes are connected with the tubes (called tracheae), and a great many branches take the air from these tubes to every part of the body, including the wings anal antennae.