Nature's Mosquito Control

Swallows perform an impressive job of controlling mosquito and fly numbers around a rural home. They eat the equivalent of their body weight of flying insects on a daily basis.

If your home is by an open field with a body of water like a creek or a pond, you can set up nesting boxes for swallows and have them return every spring.

The warnings of the flies catching on fire if not cleaned out frequently, which was not pleasant, made us wonder if we should turn it off at night or when we go someplace, added unwanted complexities to the problem. The citronella torches and incense were ineffective and we did not like spraying or applying insect repellent just to be able to sit outside comfortably. However once the swallows began to come in the spring we saw a dramatic reduction in both flies and mosquitoes. They are the perfect natural control and a joy to be around.

One of the things I like to do during winter is to make nesting boxes for swallows out of board ends and scrap lumber. I usually pick a sunny day in late winter to set them up for the return of the migrating birds in April. I’ve got about a dozen set up on top of power poles and up high under outbuilding eaves. No matter how many more I put up, there are no vacancies by the mid May.

There's one peeping out of the entrance.

According to the Washington State Department of Fish and Wildlife, half of the bird species that breed in Washington migrate south to tropical Central and South America. That is a distance of between 3000 to 4000 miles. The swallows gather in large flocks in late summer, early fall to begin their flight south. They return close to the same dates every early spring to the same nesting boxes. It is just incredible that these small birds fly a round trip distance of nearly 8000 miles every year back to our yard, I feel honored and humbled by their appearance.

Mr. and Mrs. Tree Swallow

Here is a simple nesting box for swallows. It is important to keep the entrance hole 11/2" in diameter. A larger hole will invite bigger birds like starlings, smaller and they will have problems getting in and out especially when the female is pregnant.

The box should be rain proof and vent holes on the bottom are not advised as ants can come in and disturb the nest. It is important to place the nesting box at least ten feet from the ground. We have ours on poles.

Metal must not be used in the construction of the box, i.e. metal roof, they get too hot and too cold. In areas where summer temperatures can get very hot for extended periods like central Washington where 90 degrees and above is common, the box must be sheltered from the midday sun, under an eave or on a north side of a structure.

The nesting box should be cleaned out every one or two years to deter possible infestations of mite or other parasites. This would be especially important in areas where winter temperatures do not get cold enough.

Audubon Society Tree Swallows
Bird Web
Woodworking Projects for Backyard Wildlife