Forest Preserve District of Cook County, Illinois
Nature Bulletins
Newton Home Page

Introduction and Instructions

Search Engine

Table of Contents



Nature Bulletin No. 78   August 10, 1946
Forest Preserve District of Cook County
Clayton F. Smith, President
Roberts Mann, Superintendent of Conservation

These August nights you will hear the katydids: "Katy did. She did. She didn't." There are two notes more often than three. Though harsh and monotonous it is a melancholy sound because it means that summer will soon be over. They sing only in late summer and early fall. The farmer, whose life and livelihood are governed by the weather, shakes his head and reckons the first frost will come six weeks after the katydids begin to sing. The males make the call, although in a few species the female can give a feeble chirp. It' s strictly a male debating society.

The katydids, like their close relatives: the grass hoppers and crickets, have two pairs of wings. The fore pair -- upper when folded back -- are larger and stiffer than the soft membranous rear or under pair. The song is made by scraping a toothed file-like edge on the base of the left fore wing across a hard knife-like edge on the right fore wing. Grasshoppers sing by rubbing their hind legs against their wings, whereas crickets rub the upper and lower pairs of wings together.

There are many species of katydids but only a few are common in this region. Some live in trees; some in meadows. Some are brown, some spotted, some green, depending upon the species and the vegetation upon which they live. Some sing at dusk and dawn; some sing all night. Some lay their eggs in crevices on the soft bark of a tree; some lay them on a leaf; some split the edge of a leaf and lay their eggs between the two layers. Held in captivity, these have been known to split the edge of a piece of writing paper to lay their eggs.

Our common broad-winged katydid is a large green hump-backed slabsided fellow that lives in trees and is rarely seen. They have a very long delicate antennae, long hind legs, and are good jumpers but their night is usually short.

The adults all die in the fall. The eggs lie dormant through the winter and hatch in late spring directly into a miniature katydid which grows, molts its skin, and repeats the process until mature. There is no larva or pupa stage.

If you will notice carefully, they sing faster on hot nights. On cold nights they are silent except perhaps for a few hoarse chirps.

"Katy did. She didn't" Make up your mind!

To return to the Nature Bulletins Click Here!
Hosted by NEWTON

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (, or at Argonne's Educational Programs

Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Sponsered by Argonne National Labs