Grade: all
Subject: Science

#645. Mealworms in the Classroom

Science, level: all
Posted Mon Sep 28 10:14:04 PDT 1998 by Ken Baxter (
Beall High School, Frostburg, MD 21532
Materials Required: A dozen mealworms, some cereal or chicken feed, container
Activity Time: Months to years, ongoing
Concepts Taught: Decomposition, Metamorphosis, Niches, Habitats

This is a classroom display that may be used for collecting
data or sketching but mainly provides an interesting source
for discussion.

Purchase a dozen or so mealworms at a bait shop or pet store
and place them in a large transparent container such as an
empty pretzel or large juice jar. Add the cereal, oatmeal or
other kind of feed. The feed needs to be more or less powdered
so, if need be, blenderize it first. Toss in an apple core,
banana peel, or potato (this is for water and trace minerals)
and the culture is in business.

Eventually, the kids will notice the mealworms changing into
white, hard pupae and some time later into beetles. The
beetles seem to die quickly and many kids will assume the
culture has died. Later, depending on conditions in the
culture, movement will be detected which is soon found out
to be very small mealworms. And life goes on. My culture has
been going since 1985, has nothing done to it over summer
except a dose of feed added just before the end of school
year. I put more feed and a potato in when returning in
August and things start right up again.

Things to note :
1) Mealworms are of the genus Tenebrio and won't escape
from the container. Some members of this genus are actually
used in preparing skeletons because they are carnivores.
2) The three metamorphosis stages are all easily seen.
The adult beetle stage doesn't eat but, like salmon, quickly
reproduces and dies young,
3) The mealworms are excellent decomposers, immediately
finding whatever vegetable matter is placed in the culture.
It's fun to toss a banana peel or apple core in and let the
kids see how long it takes for the first hole to be drilled.
4) These guys are pretty good experimental animals for
seeing how they sense different things - attracted or
repulsed - and also for different kinds of nutrition. E.g.
give each group 10 and weigh them occasionally when they have
different breakfast cereals for food.

Have fun. If you get too many, you can use some for fish bait.