Does anyone know anything about earthworms? Any DU biologists?

[Maddy McCall]

My kid has to do a science experiment. You put soil in a jar, then cornmeal, then three earthworms, and cover the jar top with foil. Then you wait 24 hours and observe. What are they doing?

THEN, you wrap the jar with dark paper and wait 24 more hours, and observe what they are doing then.


So my son did part one--the cornmeal and foil part, and a couple of hours after putting the earthworms in, one of the earthworms was dead on top of the cornmeal. I know that this is not what the experiment was to prove.

I like this learn-by-doing type of assignment, but can anyone tell us what to expect? Or what the point of an experiment like this is; in other words, what observations are we to look for?

He has one bad test grade in science, and doing this experiment will give him a 100 to replace the bad test grade...but I know his teacher well enough that, if he says that one of his worms died, she will deduct points. (I know, she shouldn't, but lots of things that shouldn't happen do at his school.)

Thanks to anyone who can offer advice.

[WannaJumpMyScooter]

1. Well, the true scientific answer would be

record what really happened. ie That the earthworm died.

Sometimes you have to do things more than once.


Corn meal is what worm growers feed earthworms. I would expect they would be down there chowing down on it.

[burrowowl]

5. Yes but

mixed with moist soil!

[vajraroshana]

17. Exactly!!!

I can't believe the teacher is going to deduct points if the worms die!!

That really pisses me off; that isn't what science is about, dammit!

It reminds me of a lazy republican (yes, he really was; a true dittohead too) lab partner I had in college who would say (about thermodynamics experiments) "first you draw the line on the graph to get it the way it's supposed to be, then you plot the points" the points being the actual experimental observations...bah! Thermodynamic experiments are notoriously difficult to perform, you learn a hell of a lot though by messing them up.

That's what makes me pissed about this. Children could learn that ecosystems are fragile and delicate and can't be so easily artificially formed, instead these children have to learn how to get an "A"; I'll bet some kids' parents are going out and buying replacement earthworms.

Damn this makes me mad.

[benddem]

2. First thing I'd do

is take out the dead earthworm and put in a live one. I have red wigglers not earth worms but I think the worms would bundle together to get away from the light. In the dark they would be working.
Hope some on gives you some good info.

[cdsilv]

3. cornmeal will absorb moisture...

and earthworms need moisture - but not too much (ever seen 'em after a hard rain)?

Perhaps the cornmeal absorbed enough moisture to mimic a hard rain on the surface? Don't really know.

I do know you should take the worms and go fishing!

There will be other science courses in the future, don't get all wound up about this one.

Sorry if this doesn't help

[burrowowl]

4. Cornmeal!

Damn things probably dehydrated.
The soil they live in is moist. Like here in ABQ, they croak in sand, some live in moist flower beds and rarely lawns since a tad too dry.
Dry cornmeal, I suppose you were to weigh them before putting them in and then weigh them dead and see how much moisture they lost, To encourage earthworms my grandmother would put used coffee gounds and orange peels in her flower beds.

[mike_c]

6. this is a variant of the commercial culture method....

...using soil instead of the more usual moist peat moss or something similar. The corn meal is a high quality food resource. I presume that the "outcome" of the experiment should have been inactivity in the light, evidence of activity in the dark (surface feeding, churning of the substrate, cast formation, etc), possibly with production of reproductive cocoons. Worms are active in the dark.

Is the soil moist? Not too wet, but a little moist? If not, that might explain the mortality. Earthworms respire through their skin, so they need to stay moist (all animal respiratory surfaces must be moist).

[Maddy McCall]

8. Yes---The soil is moist, but the cornmeal is dry.

I was thinking that this was an experiment to see how they respond to light...so perhaps when we cover the jar with the dark paper, the two surviving earthworms will pull the surface cornmeal down into their burrows?

Thanks for your input!

[SemiCharmedQuark]

7. Ahhh, I actually know this one!

Putting dark paper around the jar will encourage the worms to burrow along the sides of the jar since they will no longer be avoiding the light. You should see their holes start appearing.

[Maddy McCall]

9. Thanks Thanks Thanks!

That is what I am thinking, too. Bless you!!!

[SemiCharmedQuark]

11. No worries!

Make sure he includes that while they are burrowing when the jar is not wrapped they are doing so in the inner part of the jar and avoiding the edges where light touches. I had a hateful teacher like his seems to be when I was in school...ugh.
Best of luck to you son!

[Maddy McCall]

15. Thanks again...

I will tell him exactly what you said.

Thanks so much!

[bloodyjack]

13. That is a terrific sig pic

[Maddy McCall]

10. EVERYONE, THANKS FOR YOUR INPUT...

We will write the first worm off as a casualty of the scientific method and continue on with the experiment as planned. Thanks for all your advice!!!

DUers are the smartest folks in the world!

[mike_c]

12. you might also want to look at this USDA lesson....

http://www.agclassroom.org/teacher/pdf/prairie/prek_1/7_WormWatch.pdf

[burrowowl]

14. Looks like the teacher

jumped a few steps in the science experiment.
Only dry cornmeal equals DEAD worms!
Asshole!

[Maddy McCall]

16. Thanks...I just printed that out for my son.

[burrowowl]

18. So has the life expectancy

with a change in humidity changed earthworm mortality rate?