Nature Bulletin No. 315-A October 5, 1968
Forest Preserve District of Cook County
Richard B. Ogilvie, President
Roland F. Eisenbeis, Supt. of Conservation
Out in the woods you may have seen a strange creature, with a body
like a plump brown grain of wheat, scamper across your picnic lunch,
teetering on eight very long and hairlike legs. That was a Daddy-long-
legs or Harvestman, a harmless relative of the scorpions, spiders, mites
and ticks. You won't find much about it in books. When wheat or oats
were cut on the farm, there were sometimes hundreds of them on the
binder at quitting time. We children used to pick one up by a leg and
say, "Grand-daddy-long-legs, tell me where the cows are". The other
seven legs waved wildly in all directions so then we listened for the
Unlike the spiders, the abdomen of the harvestman is divided into
segments and it has no "waist". Instead, the head, thorax and abdomen
are grown together into a compact oblong body. Neither do they spin
webs or build nests. On top of the head is a black dot which, under a
lens, is seen to be a knob with a little shiny eye on each side.
Apparently these primitive eyes can detect a moving object several feet
away. Underneath is a pair of little lobster-like pincers used to grasp,
tear and stuff food into its mouth, to fight other harvestmen, and to
frequently clean its legs.
Those seven-jointed legs are unique. The Indian name for Grandfather
Graybeard, as some call it, meant "Feet of Hairs". If we had legs in
proportion they would be 40 feet long! The second pair is the longest --
about 2 inches in our common kinds -- and their extremely sensitive tips
are used to explore its path, search for food, and warn of danger. The
fourth pair is next in length and the first pair is shortest, unless "Daddy"
has lost a leg and is growing a new one. Recently, while examining a
harvestman she suddenly scurried away, leaving a leg between our
fingers. It continued to twitch spasmodically for 21 minutes.
About 1900 species of harvestmen are distributed over the world in
forests, fields and other land habitats, although they can and do walk on
water. Some of those in the tropics and our southern states do not have
such long legs. We have 60 or more American kinds and the adults of
all but one of these die with the coming of winter. They mate in late
summer and autumn. While the smaller male drives away rivals, the
female lays a few eggs at a time in the soil, some crevice, or rotten
wood. This is repeated until she becomes merely an empty shell. In
spring the newly-hatched young are white miniature editions of the
adults. They soon darken and, as they grow, shed their skins like many
insects do. They eat a wide variety of animal food, both dead and alive,
as well as vegetable matter and juices. We saw one eat the little ants on
a crumb of bread and then eat part of the crumb.
Usually leisurely in their movements, they can move rapidly with the
body swung below the pumping "knees". Although frequently active in
daytime, they are primarily night prowlers and solitary in habit.
Sometimes, however, several will form a tangled mass of bodies and
legs and remain immobile unless prodded into activity. Then they stink.
A pair of scent glands, opening near the bases of the first pair of legs,
produces two secretions: a milky one with a sickish sweet odor to
discourage enemies, and a clear one to lay a trail which may be
followed by other harvestmen. Some people use perfume for the same
To return to the Nature Bulletins Click Here!
Update: June 2012