Gardening: Nocturnal mammal the bat can be enticed to hang around but beware of rabies-carrying animals

Downtown Austin, Texas, is known for nightlife of live music, dancing and dining. I got to enjoy some of that while I was at a conference there last week.

However, people don’t just come for the night life. Each evening, a thousand or so folks find their way to the South Congress Street Bridge that spans the Colorado River to watch the evening flight of over 3 million bats from under the bridge and out into the urban hinterlands to catch bugs. It takes about 20 minutes for them all to fly out of the long concrete slots in the bridge’s decking structure. We stood in awe as clouds of them skittered off into the fading Texas sunset.

Bats are found all over the world and are the only true flying mammal. According to the Washington Department of Fish and Wildlife, we have more than a dozen different species of bats that eat a wide variety of night-flying insects during the warmer parts of the year. A nursing female bat can consume her weight in bugs each night.

Bats use a form of sound radar to identify their prey. They emit a high-pitched sound that bounces off their prey that they then hone in on. Because they are following their targeting sounds, bats tend to fly in very erratic patterns and catch the insect with their tail or wings before eating it on the fly. While most of the sounds are too high for the human ear, we can hear a clicking noise when the bats are around. A bat can fly up to 6 miles an evening seeking insects.

During the day, bats return to dark places in buildings, caves, hollow trees, rock crevices, tunnels and attics. They will hang upside down either singly or in large groups. From late October into early April, they hibernate in spaces that are cool but above freezing with high humidity. “Pups” are born in the spring and are flying by July and August.

If you want to encourage bats to hang around (pun intended), check out the Washington Department of Fish and Wildlife web link for bat house construction and siting instructions. A bat house should be about 2 feet tall and 14 to 16 inches wide. The house can be a single chamber three-fourths of an inch to an inch wide or multiple chambers. Place the houses in a quiet area on a pole in full sun to absorb the sun’s heat which the bats love. Painting the box with several coats of black paint will help with heat absorption.

A note of caution: Bats can carry rabies which is fatal to humans and other animals if not treated. Dogs, cats and ferrets need to be vaccinated. Never pick up with bare hands a bat you find laying out in the open and keep children and pets away from them. This is not normal behavior for the animals, and they may bite and inflict rabies into the wound. If you are bitten, seek medical attention immediately.