|
Living with Critters in Your Classroom
By Teri Dannenberg and Terry Shaw
FOSS Developers
Several FOSS modules require living organisms for students
to study and experience—everything from radish sprouts
and ryegrass to crayfish and cockroaches. The new middle-school
Diversity of Life Course, would not be complete without living
organisms. They are an integral part of the learning environment,
but by their very nature require more attention than the nonliving
components.
Before the Critters Arrive
Prior to beginning a course that uses living organisms, you
need to be prepared for their arrival. Ask yourself several
questions:
- How much space do they require?
- What kind of container do they need?
- How much light do they need?
- What temperature is best?
|
Most of these questions are covered in the materials or the
getting ready sections of the Diversity
of Life teacher guide.
Here are a few things to keep in mind when ordering.
- Most biological supply companies do not ship on
Thursday or Friday to make sure that the organisms
do not arrive on the weekend.
- Plan to receive the organisms about a week before
you need them in class.
- There are usually a few fatalities after the stress
of shipping. You don’t want a student’s
discovery of a dead critter to be his or her first
experience with a new organism. If you live in an
area of extreme hot or cold temperatures, consider
this when determining the shipping method. Consider
this actual experience: a shipment of crayfish arrived
on a hot Texas Saturday and sat in the mail truck
until Monday. The mailman wasn’t happy, neither
was the teacher. The overnight shipping fees may be
worth the extra cost if they save you the frustration
of having to reorder.
|
What should I do with this roach motel now?
A student’s first reaction to an insect or snail may be
that they are dirty and covered with germs. This is an excellent
time to discuss the difference between an organism that is found
in the wild and one that is raised in captivity. The organisms
that have been selected for the FOSS modules and courses are
carefully chosen from reputable suppliers to prevent exposure
to any potentially harmful diseases. Even so, it is a good idea
to have students wash their hands after handling any organisms.
Living organisms increase the interest and enrich the experience
of science for students, but a dilemma usually comes up at the
end of the course, "What do I do with them now?" It
is easy for us to just stop watering a plant. The soil and dead
plant can be easily added to the garden or compost. But animals
pose a much bigger problem. While plants and animals are all
living organisms, we have a closer kinship with the animals,
even the buggy sort.
Some organisms are easy to get rid of. You can usually find
a student and parent willing to adopt a goldfish or guppy. You
can usually be comfortable with the thought that your fish will
live out their days in a glass bowl.
Insects and snails are different. After a time in your classroom,
you and your students will probably begin to see these organisms
as gentle and interesting to have around. But not many parents
will welcome a box of creepy-crawly friends into their living
room. Madagascar hissing cockroaches usually evoke an initial
negative response from everyone. Some organisms, such as land
snails, are also considered agricultural pests. Finding a safe
and humane way to dispose of these animals is important.
Be very hesitant about giving insects to students as pets,
unless you have personally talked to the parents and they
are fully aware of the care and feeding of these organisms.
Parents must understand how to dispose of them. The animals
were not born in the wild so they should never be set free
in the wild. In most areas there are severe restrictions for
releasing any insect, native or not. Madagascar hissing cockroaches
are certainly not native. Under no circumstances should
you release them to the environment.
Have a plan for how you will get rid of organisms before you
receive them so that you don’t need to make a spur-of-the-moment
decision. Contact the biology departments of local universities,
community colleges, and high schools. Pet stores, especially
those that specialize in snakes and lizards, may be interested
in hissing cockroaches. If you have a local biological supply
company in your state they may be willing to take them. Don’t
expect to be able to sell the organisms to them—they
are usually just willing to take any extras off your hands.
An ideal situation would be to locate a teacher in your district
or area willing to maintain the organisms and share them with
everyone.
If you absolutely have to get rid of them, the most painless
way to euthanize them is by placing them in a closed container
and putting it in the freezer for a couple of days. Then dispose
of them in the garbage.
Frequently Asked Questions About FOSS Organisms
Land Snails
• What if they escape?
Land snails are easy to take care of and deceptively fast.
Never leave the container open or you will be finding snails
in very unexpected places. If they do escape, look under shelves
and behind books. They like dark places.
• What should I do with them over student
holidays?
They don’t need to be fed and watered over holidays.
If their habitat dries up, they will simply estivate until
you return. Don’t leave any wet food in the container
that may spoil.
With a few sprays of water when you return, the snails return
to their old selves. When they wake up they are very hungry;
so make sure you feed them unless students will be observing
their eating habits. Then it is better for them to be a
bit hungry.
• Will they breed?
Land snails will breed in captivity. Cover the bottom of
their container with at least three centimeters of moist
potting soil. Look through the bottom of the container for
clusters of small, white, BB-sized eggs. The hatchlings
are tiny versions of adult snails. They can escape through
the holes in the lid of a six-liter container. Cover the
inside lid with nylon mesh and tape in place. This will
keep the babies inside.
• Should I keep the males and females apart?
You can’t. Snails are hermaphrodites, so it just takes
two, any two. If you happen to see a love dart protruding
from the neck of one of your snails, that is a sure sign
they have mated.
• Why does the shell feel soft and fragile?
If the shells begin to get thin and fragile, it is very
easy to damage them. This is a sign that the snails are
not getting enough calcium. In the wild they graze on high-calcium
sources, such as limestone, cement, and dirt. To add some
calcium to their diet, place a few pieces of chalk or some
antacid tablets in the container. Fruit-flavored antacid
tablets yield some surprising results upon egestion.
• What do I do if they won’t ship snails to
my state?
Snails are an agricultural pest and strictly regulated in
some states. Some companies cannot ship snails across state
lines. Look for a biological supply company within your
state or plan on collecting snails from the garden. The
USDA will issue permits to use snails for educational purposes,
but this can be a long process. If this is the way you have
to go, start the process early. The permits can be found
at http://www.aphis.usda.gov:80/ppq/permits/plantpest/snails_slugs.html.
Madagascar Hissing Cockroaches
• Do they bite?
They have chewing mouthparts, but they are so small that
they do not pose a danger to human fingers.
• What about allergies?
Cockroaches do not seem to be allergic to anything. Seriously,
one of the reasons we chose them is that they do not seem
to cause allergic reactions, carry parasites or diseases,
or bite.
While we have not found any reference to allergies associated
with hissing cockroaches, some people may be allergic to
molds that form in damp substrates. It is important to keep
the water dish positioned so that water does not wick out
into the substrate. More frequent changing of the substrate
will also keep allergens in check.
• What should I do with the eggs if any appear?
The females carry the egg case inside their abdomens. You
won’t see them, except for a short time when the egg
case is forming, and you see it protruding from her abdomen.
It is then drawn back into a special cavity where the eggs
mature for about 60 days. The nymphs emerge in what appears
to be a live birth. Keep a little peat moss in the bottom
of the tank and have something for the nymphs to crawl under
or into, such as a paper towel tube.
• Should I keep the males and females separate?
It is not necessary to keep them separate unless you absolutely
do not want them to breed. However, the females may be carrying
egg cases when you receive them. They are not aggressive
and a mix of sexes and ages can be kept in the same container.
• How long do they live?
Madagascar hissing cockroaches live about two years. But
a healthy breeding community can be kept indefinitely.
• What should I do if my school doesn’t
allow us to have them in the building?
There is an almost universal aversion at the mention of
cockroaches. Visions of herds of huge cockroaches scurrying
across the floor in the night come to mind. But remember
these are not the same species as the common household or
German cockroach. If you encounter resistance from administrators
or other teachers, you may want to direct them to some of
the websites listed at the end of this article. Assure them
that the cockroaches will be secure and unable to escape.
You may have to go the extra mile and over-secure them.
Smear a wide line of petroleum jelly around the inside,
top edge of the container. They can’t stick to this.
Keep the container covered with a screen or glass lid. The
larger the aquarium, the less likely they are able to crawl
out.
Hissing roaches are much slower moving and not nearly as
prolific as other insects. They are not a health threat.
If the name "roach" has bad connotations, call
them something else. Some pet stores sell them as Madagascar
hissing "beetles." They aren’t beetles,
but mothers would probably be more likely to let their children
buy a beetle than a roach. It’s all in the marketing.
(Note from Teri: I have to admit, I was hesitant to work
with them. They reminded me of large, flying Palmetto bugs
I once saw in Texas. But after a time of watching them in
my office and observing students warm up to them, I did
see that they are actually fascinating creatures. Don’t
expect them to be received with the same open, loving arms
that a cute, fuzzy bunny might get, but acceptance can be
gained.)
• What should I do if they escape?
Catch them. They are not nearly as fast as common German
cockroaches and since they lack wings they are not going
to fly away. Look under things for them. Use a piece of
banana for bait and have something (e.g., an egg carton
or paper towel tube) for them to hide under or inside near
the bait.
The best way to prevent escapees is to coat the inside top
edge of the aquarium with petroleum jelly. A nice goopy
border about six centimeters wide will keep adults and nymphs
from climbing out. They will squeeze through any crack and
climb glass or plastic, but they will not cross Vaseline.
(Note: In the three years Terry Shaw had them in his classroom,
there were only two escapes. Both happened when a student
thought it would be a neat idea to take them to another
class and cause a commotion. To prevent this from happening
in your classroom, keep them in a place in the room that
you can supervise or that the students can’t easily
access.)
• Can I feed them to my lizard?
Yes, but the exoskeleton of the adults is pretty tough.
Your lizard would probably like the smaller ones better,
especially just after they have molted. They are almost
white for a day or so after they molt. During that time
the exoskeleton is fairly soft and easier for lizards to
digest.
Many people raise these cockroaches to feed to insect-eating
lizards. One advantage is their ease in reproduction and
the absence of offensive smells from their feces. They are
not cannibalistic, so it is safe to keep the nymphs with
the adults in the same container. In fact they seem to prefer
crowded conditions. Like all roaches, they like to be in
contact with as many surfaces as possible.
• How do I humanely get rid of them?
Place the cockroaches in a container, and put the container
in the freezer for a couple of days. After the cockroaches
freeze, you can throw them in the garbage or use them for
dissection. Madagascar hissing cockroaches are much larger
than preserved grasshoppers, and internal structures are
much easier to see on frozen specimens than on preserved
ones. How-ever, if you use them for more than one day, you
will need to keep them refrigerated between classes so they
don’t spoil.
• If I do get them, how long will I have to
keep them in the classroom for the lesson?
The activities that use the roaches take about five or six
class periods. Several teachers can share the same set of
cockroaches. They only need to be in each classroom that
length of time. It helps for them to be visible in the classroom
while the students are studying them so that they can see
their behavior during the non-stressful times when they
are not being handled.
Resources
Websites:
Madagascar Hissing Cockroaches
Madagascan Hissing Cockroach Care Sheet
http://www.a1reptiles.com/a1mhrcare.html
University of Kentucky Entomology/Madagascar Hissing Cockroach
Site
http://www.uky.edu/Agriculture/Entomology/entfacts/misc/ef014.htm
Snails
Raising Snails/U.S. Department of Agriculture
http://www.nal.usda.gov/afsic/AFSIC_pubs/srb96-05.htm#Introduction
All About Snails
http://www.kiddyhouse.com/Snails/snail.html
Milkweed Bugs
Milkweed Bug Information/Center for Insect Science Education
Outreach at The University of Arizona
http://insected.arizona.edu/milkinfo.htm
Amazing Insects (click on Milkweed Bugs)
http://www.ivyhall.district96.k12.il.us/4th/kkhp/1insects/milkweed.html
General:
Using Live Insects in Elementary Classrooms for Early Lessons
in Life/Information Sheets
http://insected.arizona.edu/info.htm
Books:
There are a few excellent books on the care of classroom
animals. One favorite is They Don’t Have to Die:
Home and Classroom Care for Small Animals, 2nd edition,
by Jim Dunlap, 1996, Wordware Publishing, Inc. ISBN 1-55622-533-4.
You will find practical advice, inexpensive solutions, and
a bit of humor.
|
