Beneficial bats

By Scott Stegenga
For The Courier

Mosquitoes are very efficient at finding the smallest source of calm water for egg laying. When it comes to reducing the mosquito population, dryer conditions are helpful but not the only factor at work. An animal that will not win many awards in a beauty contest that is coming to our aid is the bat, the only flying mammal.

Beneficial bats

Beneficial bats

Most of us have heard about a bat’s “sonar” method of feeding. This is actually called echolocation, where very high-pitched sound waves are used to zero in on flying insects. The bat reacts to any reflected sound waves that bounce back to them off even the tiniest of airborne insects. Bats can only identify prey at short range and so exhibit erratic flight patterns as they seek out their food. Occasionally when a small pebble is tossed into the air where bats are feeding, one will swoop at the object before the realization that it is not something to consume. The type of feedback perhaps indicates that the stone is much too dense to be food and so it is avoided.

Once a bat does locate edible prey, it uses the membrane of the tail and wings to corral the insect, where it can snatch it up with its teeth. This feeding technique is very successful, as bats can consume more than 500 insects an hour and about half their body weight or more in a night! Although many birds help consume various insect pests during the day, bats get credit for most of the mosquito control since bats feed at dusk when mosquitoes become most active. Besides rodents, there are more species of bats than any other mammal, and they are found everywhere expect in polar regions.

Bats have been the target for many superstitions and fears. They are not interested in attacking people and do not fly into a person’s hair as one myth has it. They can carry rabies, but it is quite rare. A fox or skunk is much more likely to be rabid. Like many animals, bats may bite in defense if handled. A loose bat in the house may be persuaded to fly out an open door or can be safely caught as they hang on a wall or ceiling by putting a container over them and sliding a firm piece of poster board between the opening and wall to secure the container before taking it outside to release the bat. The main problem of having a bat roost in or on a building are their droppings, called guano, that accumulate below. Roosting bats can cause a mess on a floor, but bat guano does make excellent fertilizer. Guano was even used in the Civil War to produce potassium nitrate for making gunpowder.

Unfortunately, bats are facing a deadly enemy. A disease known as White-Nose Syndrome is caused by a non-native fungus and has been spreading west and south from the northeast. Since 2006, colonies of hibernating bats in caves have suffered staggering losses due to this cold-loving fungus that shows up mainly around the nose of the bat, causing irritation and disrupting hibernation, which leads to energy loss and starvation. It may also destroy wing tissue. More than 6.7 million bats have died so far from this disease! A decline in bat populations means an increase in insects, which affects forestry, agriculture and human health. Infected bats found dead or dying should be reported to DNR officials.

With our mild weather quickly coming to an end, instead of fearing bats, why not enjoy watching their fluttering flight in the evening, knowing they are busy keeping numerous pesky mosquitoes at bay, and let’s hope they can be spared from this latest devastating threat.