The Stray Bat Call

Late summer and early fall marks the annual period of stray bat calls to pest management and wildlife professionals in many parts of the United States. Why are these calls so abundant this time of year? How does a professional determine whether or not the bat is merely a stray bat or is part of an infestation needing to be managed? And what is the best strategy for dealing with the stray bat call? Let’s examine these questions.

The reason so many bat calls come in late summer and early autumn is due to the life cycle and colony cycles of the “house-infesting” bat species. These include the big brown bats, Eptesicus fuscus; little brown bats, Myotis spp.; and the Mexican free-tailed bats, Tadarida brasiliensis.

Generally, bats give birth during May and June. Most young bats begin flying at three to five weeks of age. But learning to both fly and obtain food is a considerable task for young bats. Consider that the pup not only has to learn how to negotiate many different natural and structural obstacles, but it must also learn to capture and eat its food literally on the fly. And, it’s doing all of this in the dark! Moreover, the young bat must learn the various navigational and biological factors enabling it to leave and return to the roost safely. Given these challenges, you might expect that any particular “graduating class of flying bats” will have youngsters making mistakes and erroneously flying into various open doors and windows of nearby buildings in the areas they are learning to fly and forage.

Disoriented young bats may also originate, however, from the same buildings in which they are born. This occurs when a nursery colony is established within a building. Young bats, attempting to learn the basics of going and coming, routinely miss exiting correctly. They also attempt to return to their family and roost though the human openings of the building (i.e., doors and windows) instead of through their “designated bat openings” that the rest of the colony is using. In addition to our buildings being in the midst of these “bat flight training grounds,” bat sightings and encounters also increase during late August and September as a result of the break up and dispersal of the local summer nursery colonies.

MANAGING THE STRAY BAT CALL. Sightings and encounters of stray bats often cause concern and sometimes even panic among homeowners. This often happens when a parent is awakened by the screams of a young child frightened by the sound and shadows of something fluttering and swooping down around their bed in the darkness of the night. Shortly thereafter, we receive the calls to come and “get rid of the bat.” Sometimes this is easy. Sometimes it is not. Let’s examine a few ways of managing stray bat calls.

1. If the homeowner is distraught or panicked, attempt to calm their fears by explaining that the bat is probably a lost and frightened young bat. The bat will not attack and rabid bats are rare. The bat will not bite anyone provided that no one attempts to handle it. It should be emphasized to the homeowner not to attempt to smash or kill the bat with a broom or a racquet. Doing so only increases the likelihood of a person contacting the bat and being bitten. (Of course, the same holds true for pest management professionals.)

2. If the bat’s location is specifically known, instruct the homeowner to not lose track of the bat (if possible). If it disappears into some other portion of the home, then the homeowner has to live with the “fear” that the bat may reappear during the next several days.

Instruct the homeowner to contain the bat in one room by closing off all the doors and access points to other interior rooms. Then, open up any windows or doors in the bat’s room to the outside and allow time for the bat to find its way out.

3. If the bat fails to leave, you can either make a service visit and remove the bat and perform a bat infestation inspection, or instruct the homeowner on how to capture and remove the bat themselves (see discussion below).

4. When the whereabouts of the stray bat is not specifically known to the client, it is not likely you will find the stray bat should you make a service visit, especially if it was a previous night’s bat. In most cases, these bats have already found their way back out. The bat may also be resting, or is close to death from exhaustion and thirst in some obscure nook or cranny within the home. Conducting an exhaustive search (looking inside closets, within air circulation systems, furnaces, underneath appliances and furniture, etc.) of the home in these cases is occasionally productive, but many times the bat is never found. Still, some families will gladly pay to have someone conduct a thorough inspection and confirm that a bat is not hiding under any of the beds.

STRAY BAT OR BAT INFESTATION? Inevitably, stray bat events prompt the question from the homeowner as to whether this was a stray bat or if their home is infested with a colony. To determine this, begin by questioning the homeowner about the history of the home and bat activity. If this is the only experience with a bat inside the home, or if there have been few sightings, most likely this is a stray bat incident. If the homeowner reports previous and repeated sightings and encounters with bats and/or of hearing scratching and squeaking noises in their walls, the home is a good candidate for containing a nursery colony. Still, this should be confirmed via a thorough inspection from April through September as follows:

1. If the attic is accessible, inspect the floor of the attic for bat droppings. If bats are present, they will usually be hanging and roosting directly above the droppings. Or, they may be hidden within a structural void nearby.

2. Outside, if the building is being used as a summer nursery colony, the bats’ emergence exits can be easily determined by inspecting along the ground next to the foundation for bat droppings. Many returning bats hang and defecate a time or two just prior to returning to their roost. By looking up above these droppings, the bats’ openings or smudge marks reveal the emergence holes. A pair of binoculars will aid in getting a detailed look.

3. If the actual bats are not seen during the attic inspection, but droppings and signs are found either inside or along the foundation, a dusk inspection of the roof line can be conducted. Either you or the homeowner can see if any bats leave the roost for their nightly feeding. Most bats leave the roost just before dark and can be easily seen and heard. Allocate about 30 minutes for a dusk inspection.

CAPTURING AND REMOVING STRAY BATS. Performing a service visit to capture and remove a stray bat can be done easily and safely, providing common sense prevails.

1. If the bat is flying around when you arrive, wait until the bat lands.

2. Slowly approach the bat with a coffee or similar size can and a piece of cardboard.

3. Slowly cover the bat with the can and slip the cardboard underneath the can to trap the bat inside. Some professionals will also bring along an insect collecting net and place the net over the resting bat. Or, to attempt to net a bat while it is flying around the room, the trick is to swing the net from behind the bat to prevent the pest from detecting the oncoming object and swaying to avoid it. This technique also helps avoid hurting the bat by swinging at the bat and hitting and hurting it with the framing of the net. Captured bats should be released outdoors and away from the property. Unless the bat was from a nursery colony from the house it was captured, it isn’t likely to return.

4. When performing stray bat removal services and bat inspections, safety considerations are important. Always wear a bump cap when inspecting attics. Leather gloves must be worn to protect your hands from bites. However, it is not necessary to wear large cumbersome or heavy gloves such as those worn by utility repair personnel. In fact, such gloves will not give you the dexterity you’ll need to handle a bat without harming or crushing it. But, on the other hand, thin, skintight leather driving gloves do not provide enough protection. Simple calfskin gardening-style gloves or an old pair of winter gloves that fit snugly and give your fingers good and easy movement are best. 5. Finally, to prevent further bat incidences, the client should be informed as to the importance of having their home pest proofed. This involves checking chimneys for caps and screening, inspecting fascia boards, repairing any loose flashing, inspecting door thresholds, gaps in window and door frames, and other pest-proofing repairs. These are all good opportunities to sell the ultimate and best aspect of Integrated Pest Management: prevention.

Contributing editor Dr. Robert Corrigan can be reached at 765/939-2829.