What will the effect of vibration
have on earthworm behavior?
Background Research
•
•
Earthworms are commonly found in moist soil around the world.
“Earthworms contribute to the growth of plants, also help break down
the humus.” (World book encyclopedia, 1983) Earthworm “bodies are
about 70% protein; rich food for many predators. Their major enemies
are insect eating birds, like robins, and mammals like moles. The
robin's ears can actually hear the earthworm moving under ground.”
(John Mertus, 1993)
Earthworms can feel the vibrations of the predators or any animal on
top of the soil, which allows them to escape quickly.
Introduction and Background
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•
Worm ‘grunting’ is a profitable business where earthworms are
harvested for fish bait. Collecting worms can generate substantial
income, but collecting earthworms also can damage the earthworm
population. One of the ways they collect earthworms is using vibration
effects in the soil to surface earthworms. “In the southeastern USA,
worm ‘grunting’ is commonly practiced to collect earthworms for fishing.
A common assumption is that vibrations cause the worms to surface,
but this phenomenon has not been studied experimentally. Worm
grunting is economically and ecologically important in localized
regions.” (Mitra, Feb. 28, 2009)
The purpose of this experiment was to determine what effect vibration
has earthworm behavior.
I predict that as the number of vibrations increase then the more
earthworms will surface, because of their animal instincts to escape
danger.
Experimental Design diagram
Hypothesis:As the number of vibrations increases, then the number of earthworms
surfacing will also increase.
Independent Variable: number of vibrations
Levels
5
Vibrations
10
Vibrations
15
Vibrations
20
Vibrations
25
Vibrations
Trials
5
5
5
5
5
Dependent Variable: number of surfaces earthworms
-Materials
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
•

•
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•


25 earthworms

soil

5 containers

5 wooden stakes

1 flat metal object
-Procedures
1) Put soil in each of the five
containers to about ¾ of the total
about of the containers (at least 1-½
inches of space from the top of the
container).
2) Place approximately 5 earthworms
in each container (let them relax
and dig underground)
3) Place a wooden stake in each five
containers avoid hitting any
earthworms.
4) Using the flat metal object, scrape
the top of the wooden stake to
recorded amount of scrapes (5, 10,
15,20, 25)
5) Observe how many earthworms
surface
6) Record observations
Data Table
What will the effect of vibration have
on earthworm behavior?
Trials
DV: number of earthworms
surfaced
IV: number of
vibrations Levels
Group 1:
Group 2:
Group 3:
Group 4:
Group 5:
Average:
5
0
0
1
0
1
0.4
10
0
2
0
1
1
0.8
15
2
1
3
3
2
2.2
20
4
3
3
2
3
3
25
5
4
5
3
5
4.4
Data Analysis
what effect will vibrations have on earthworms?
4.5
4
3.5
3
2.5
reaction rate
trial average
2
1.5
1
0.5
0
5
10
15
20
25
Levels
The graph shows that as the number of vibrations increase, the amount of earthworm
surfacing also increases.
Group 1
Group 2
Group 3
Group 4
Group 5
Conclusion
•
The purpose of the experiment was to determine if vibrations
effected earthworm behavior. The results show that as the number of
vibrations increased, the appearance of earthworms on the surface also
increase. The results shown also support the given hypothesis, which
was “ If the amount of vibrations increase, then the amount of
earthworms surfaced will also increase”.
• Earthworms can feel vibrations in the soil and animal instincts surge.
The major enemy of the earthworm is the mole which digs under
ground. Earthworms feel the vibrations and at first reaction,
earthworms suspect the predator, the mole, is digging so therefore they
dig their way to the surface to escape being captured by their predator.
Works Cited
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1) Mertus, John. “Earthworms” Emirates Natural History Group. 1993. 28.
Sept.
2010
<http://www.enhg.org/resources/articles/worms/worms.htm>
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2) Mitra, O., Callaham Jr, M.A., Smith, M.L., Yack, J.E. “Grunting for worms:
seismic vibrations cause Diplocardia earthworms to emerge from the
soil” PubMed Central. 23 Feb.2009. 28 Sept. 2010
<http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2657739/>
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3) “Earthworms”. World Book Encyclopedia. 1983.