What You Can See on Jan. 31.

From Audubon's Earth Almanac by Ted Williams and compiled in “Wild Moments,” edited by Connie Isbell, Illustrations by John Burgoyne, Storey Publishing, 174 pages. Jumping Jimmies They are smaller than chocolate sprinkles, smaller even than coffee grounds. Under a warm January sun or rain they stretch on the snow’s sagging surface, especially at the base of trees, as if some mad grocer had slashed pepper bags and danced over woods and meadow. Watch closely, and you will see them leap. They are wingless, harmless snow fleas. Not real fleas, but a species of springtail -- an order so successful as not to have changed visibly in 300 million years. The name springtail derives from the appendage under the abdomen, which, when released, can catapult the creature six inches into the air -- the equivalent of a human leaping over a four-story building. Unlike most insects, springtails lack compound eyes. They live in leaf litter, bark, and decaying logs in unimaginable numbers -- sometimes 100,000 per cubic meter of surface soil. Snow is not sterile. There is an ecosystem on and in it; and when even muted sunlight strikes it during a winter thaw the snow fleas scurry up from the forest floor to graze on the algae on its surface. Then, when night falls, they all scurry back.