Handbook of Nature-Study · Lesson LXXXVIII · Topic 13: Aphids and the insects that hunt them
88. The ant-lion
Goal: Your child can find ant-lion pits, explain how the pit traps ants, and describe the doodle-bug that lives at the bottom.
You'll need
- Dry, sandy soil sheltered from rain (under eaves, overhangs, sheds or porches)
- A spoon or trowel
- A shallow dish of dry sand
- A ruler
- A hand lens (magnifying glass)
- A nature notebook and a pencil (colored pencils if you have them)
What's in the book
Comstock's story of the ant-lion as an ogre in its den: how it digs its funnel pit, throws sand at a slipping ant, sucks its prey through hollow jaws, and later spins a round cocoon and becomes a lace-winged insect. Then Lesson LXXXVIII's leading thought, method and eight questions.
The lesson, step by step
When and where
Summer, in dry, fine sand or dust where rain doesn't reach: under the edge of a porch, beside a shed, under overhanging rocks, along sandy paths. Look for groups of neat little funnels.
Keep the big idea in mind
Comstock's "leading thought" is the one idea the lesson is meant to lead to. Read it to yourself now, and save it to share at the end, after your child has looked and answered:
The ant-lion, or "doodle-bug" makes a little pit in the sand with very steep sides, and hidden at the bottom of it, waits for ants to tumble in to be seized by its waiting jaws. Later the ant-lion changes to a beautiful insect with gauzy wings, resembling a small dragon-fly.
Where are the pits?
Where were the ant-lion pits out of doors? Were they in a windy place? Were they in a place protected from storms? In what kind of soil were they made?
Measure one of the pits. How broad across, and how deep? Are all the pits of the same size? Why?
The trap
What can you see as you look down into the ant-lion's pit? Roll a tiny pebble in and see what happens?
Watch until an ant comes hurrying along and slips into the pit. What happens then? As she struggles to get out how is she knocked back in?
Be patient; this may take a while.
Meet the doodle-bug
Scoop under one pit with the spoon and tip the sand into your palm or onto the dish.
Take a trowel and dig out the doodle-bug. What is the shape of its body? What part of the insect did you see at the bottom of the pit?
Can you see that the ant-lion moves backward more easily than forward?
It is harmless to hold, though its jaws may pinch a little.
Watch it dig
Take a doodle-bug to the schoolroom, place it in a dish of sand, covered with glass, and watch it build its pit.
Leave the dish in a quiet place for an afternoon; it digs by walking backward in circles and flicking sand with its head. Then put it back in the sand where you found it. Comstock warns that it is not worth trying to raise one, because it may take two or three years to grow up.
Nature notebook
Draw the pit from the side, like a funnel cut in half, with the ant-lion buried at the bottom and only its jaws showing. Add a close-up of the doodle-bug. Read the leading thought aloud.