Teacher Directions and Information - Animal Resources and Needs
NMGK-12 Project Number 8
This exercise is one that was modified from the Harcourt Science Text Book for 4 th grade
that Oxford School District uses. The exercise was originally designed to demonstrate the
resources (food, light, water, shelter) that an animal (meal worm) needs to survive. Meal
worms (Tenebrio monitor) are the larvae of a Coleopteran beetle (flour beetle) in the Arthropod
subphylum Uniramia, Class Insecta. The life-cycle of the beetle is also diagramed. Meal
worms can be obtained in several different ways. The easiest, but least reliable, is to find a bait
store that has them. These worms will have been kept in a refrigerator, likely without food or
water, for an unknown length of time. Mortality may be very high. A second way is to order
them from a supplier. An online source is: http://www.rainbowmealworms.com/. This
company is located in California. Meal worms/flour beetles are fairly easy to culture. They
require food (cereals, bran, wild bird meal, etc.) and some moisture, ideally supplied in the form
of a raw, dry vegetable (raw potato or carrot). The total life-cycle, from egg to adult, can take
nine months or longer.
Because of the unpredictability of the meal worms, I have also prepared a work sheet for
the same experiment but using pill bugs, or roly-polys, (Armadillidium vulgare) instead. These
animals are also Arthropods but are in the subphylum Crustacea. These are the only
Crustaceans that have adapted to terrestrial living totally and do not need an aquatic
environment for any stage of their life-cycle. They can be easily collected in most areas of the
country where there are spots where plant litter can collect. This leads to a dark, moist habitat.
I had the most luck collecting them around the border of a flower bed, and beneath a wood pile.
They do need some moisture to survive and therefore, make sure that the container you keep
them in has some moist plant litter present (not too wet). The pill bugs can be returned to their
habitat after the experiment.
The experiment is fairly straight forward. The whole experiment can be run within one
container (aquarium, large shoe box). You supply the animal with different sources of food,
light and dark area, and water and then observe them over time to determine which resources
they utilize the most. For meal worms, different kinds of cereals or brans would work. For pill
bugs, decaying plant material of different sources would be best. Water can be supplied in a
small dish. A shoebox turned upside-down, and with holes cut for access, can be used to create
a dark area. Meal worms will take longer to move to their preferred locations than pill bugs and
an experiment using meal worms should take this into consideration.
After the experiment has been run, you can discuss the needs of the animals in
association with where they are found naturally. Why are pill bugs not found in sandy,
streams? Why are meal worms found in some old, stale cereal boxes? etc.
Other activities with pill bugs and meal worms can be found online.
http://www.zooscope.oregonzoo.org/TeacherSite/t12_pill_bugs.html
http://www.wayland.k12.ma.us/claypit_hill/saylor/mealworms/mealwormsonweb.html
http://caspar.bgsu.edu/~courses/Ethology/Lab2/Lab2_Etho.html
Pill Bug Exercise
Name ____________________________________
Background:
Pill bugs are Crustaceans (related to crabs and shrimp).
Pill bugs are the only Crustaceans that live on land their whole lives.
Pill bugs are not insects, but are related to them.
Pill bugs slow down and hide when it is dry.
Pill bugs are usually found in dark, damp places.
Pill bugs have a pouch under their bodies where they carry eggs.
Baby pill bugs live in the pouch for about 6 weeks.
Pill bugs live for up to 3 years.
Pill bugs are inactive (do not move or eat) in the winter.
Observe, compare, classify:
What do pill bugs look like?
How can you tell that they are not insects?
Are they active or sluggish?
Where are they hanging out?
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Experiment (measure, gather, record, interpret):
Day 1:
Place a dish with 10 pieces of oak leaf at one end of a box
Place a dish with 10 pieces of maple leaf at the other end of the box
**Make sure that all leaf pieces are of equal size.
Place a dish with a little water in the middle of the box
Cover the water dish with an upside-down shoe box
Place 10 pill bugs (of the same size) into the box
Put the box into a quiet, dark area over night
What are some of the control variables that we have?
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Day 2:
Bring the box out
Find the 10 pill bugs without disturbing them
Record where each one is located (you can do this with a drawing)
Remove the pill bugs from the box
Record how many Oak leaf pieces and Maple leaf pieces have been eaten (count
the number left)
Number of Oak leaf pieces eaten _______________
Number of Maple leaf pieces eaten ____________
Predict and Infer:
Make conclusions about what needs the pill bugs have.
Do pill bugs need water?
Do pill bugs need Oak leaves?
Do pill bugs need Maple leaves?
Do pill bugs need dark?
Write a sentence telling the needs of a pill bug.
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Meal Worm Exercise
Name ____________________________________
Background:
Meal worms are insect larvae (babies).
The four stages in a meal worms life-cycle are: egg, larva, pupa and adult. (see diagram)
Adults are known as Flour Beetles or Darkling Beetles.
It takes several weeks to grow from an egg to an adult beetle.
A female flour beetle will lay up to 500 eggs in her life.
Adult beetles only live 2 to 4 weeks.
Meal worms eat mostly plant material (grains, bran, cereals, potato, carrot).
Meal worms are usually found in dark, damp places.
Meal worms were introduced to North America from Europe.
Observe, compare, classify:
What do meal worms look like?
How can you tell that they are insects?
Are they active or sluggish?
Where are they hanging out?
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Experiment (measure, gather, record, interpret):
Day 1:
Place a dish with 10 Corn Flakes at one end of a box
Place a dish with 10 Frosted Flakes at the other end of the box
Place a dish with a little water in the middle of the box
Cover the water dish with an upside-down shoe box
Place 10 meal worms (of the same size) into the box
Put the box into a quiet, dark area over night
What are some of the control variables that we have?
_____________________________________________________________________________
Day 2:
Bring the box out
Find the 10 meal worms without disturbing them
Record where each one is located (you can do this with a drawing)
Remove the meal worms from the box
Record how many Corn Flakes and Oatmeal Flakes have been eaten (count the
number left)
Number of Corn Flakes eaten _______________
Number of Oatmeal Flakes eaten ____________
Predict and Infer:
Make conclusions about what needs the meal worms have.
Do meal worms need water?
Do meal worms need Frosted Flakes (sweet)?
Do meal worms need Corn Flakes (not sweet)?
Do meal worms need dark?
Write a sentence telling the needs of a meal worm.
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Meal worm (Tenebrio monitor) Life-Cycle
Larvae
(9-12 instars; 6-9 months)
Pupa
(6-18 days)
Eggs
(4-18 days)
Adult Beetle
(2-3 months)