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Name: Becky G.
Status: student
Age: 12
Location: N/A
Country: N/A
Date: Saturday, June 01, 2002

We live in the midwest and have a problem with earthworms crawling into our swimming pool. Why do they do that? After a really bad rain we can have over a hundred, but in the morning following a dry night we'll have about 10. Is there any thing that we can put along the border that will make them stop crawling to the pool?

I am sorry that I cannot tell you how to keep the earthworms out of your pool. I can tell you that earthworms come to the surface at night, especially after rain soaks their underground burrows, and they may go to your pool because they are attracted to the water, or maybe just crawl in by accident. Maybe a pool maintenance or supply company could help you with keeping them out.

J. Elliott

Becky, Long periods of rain or very water soaked soil will bring the earthworms to the surface. The reason seems to be related to the fact that they breathe through their skin, and the process of diffusion of oxygen is not efficient enough when the ground is soaking wet. Water does not hold the amount of oxygen as does the air. Earthworms need aerated soil for this reason; they actually help aerate the soil with their continuous tunneling. When they get to the surface under these very wet conditions, they often find that their is a great deal of water on the surface as well and they tend to move around probably seeking drier areas for better oxygen diffusion, it is believed. There have been some studies to confirm this idea.

Now when they move around they do not have anything but the ability to detect light. Light is something they avoid. During the daylight period, this may add to the reason they move around; seeking a dark area. Daylight is a dangerous thing! Remember the early bird gets the worm? Earthworms normally come out at night for it is dark, they mate on the surface exclusively because it is difficlut to find mates underground. Normally, however, you will not find the earthworm moving around to any great extent at night.

I have no idea how your swimming pool is designed. I would hypothesize that it does not have a lip around the perimeter of the pool for these worms would have a difficult time climbing over it. The pools in my area do not see earthworms because they all have this feature. If you do, then there is something else involved.

You could purchase from a garden center some rounded edging that would help this situation.

Now, there is one thing you must re-think. Earthworms are as far as being a pest as a organism can be. They are very helpful in providing nutrients to the soil, help increase the amount of soil and serve by their presence to indicate that the soil environment is in good condition at least.

I hope I have helped.

Steve Sample

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