Humane Bat Exclusion

Bat Exclusion

How to evict or get rid of bats from your roof or ceiling
Humane Bat exclusion refers to the use or application of Eco-friendly methods that aren’t harmful to bats when being evicted from roof, attic or ceiling where they are a nuisance to homeowners.

About Bats

Bats are mammals of the order Chiroptera, the second largest order of mammals after Rodents (Rodentia). Bats are present all over the world except for extremely cold and desert regions.

Habitat

Naturally, bats used to roost in caves, dead tree bark and other natural structures. Nowadays in urban areas these kinds of roost sites are no more, yet in most cities especially the suburban parts availability of prey for bats is huge as a result of trees, ever flowing rivers, small dams, ponds, pools and beautiful gardens. All these combined make an irresistible habitat for insects that most bats prey on. Bats have adapted to foraging in city/urban environment which resulted in them requiring places where they may roost, breed and nurture their young and sustain their livelihoods in cities thus led to most insectivorous species roosting in man-made structures like ceilings, crevices on building walls, thatch roofs, in lodges or getaway homes.

Bat species and Diet

A bat’s diet spans a number of insects, fruits and nectar. Most bats we see flying around us at night which have adapted to roosting in our ceilings or roofs fall under the Microchiroptera (Microbats) suborder. These are the echo locating bats that rely on echolocation to navigate and prey for insects which they feed on. These insects include midges, beetles, moth mosquito and etc. Frugivorous and Nectarivores fall under the Megachiroptera (Megabats) and they feed on nectar and fruits.

How do you tell you have bats in your roof and how to identify their entry/exit points?

Squeaking and scratching can be head from where bats may be roosting, droppings (guano) can be seen on the floor under the entry/exit points. White lines or streaks from bat urine, dark brown greasy marks from bat’s body oils are also signs to look for. If the above mentioned isn’t helping in your situation, then a “BAT WATCH” is the best option to take. About half an hour before dusk, station people on all sides of the house/building so as to see bats when exiting their roost as usual to forage for food.

Breeding, breeding season, weaning and hibernation.

Like all other mammals, bats give birth to a live young one too. Most species produce one to two young ones (bat pups) a year. In the southern hemisphere breeding occurs in November and December even though sometimes it can be as early as October. The weaning stage takes place in January. This is the period when young pups cease to be dependent on parents and start going out to forage for food. In winter bats hibernate so as to save energy as food is usually scarce during winter season. Some bats migrate to their hibernation quarters; in Gauteng most bats don’t migrate but they become less active as they are sometimes seen fly out even though not in a regular basis.

When is the right or appropriate time to do a bat exclusion

If you are in this industry this is one of the questions you come across with from most of the clients who want to evict bats but don’t want them dead.

In order to do a successful bat exclusion that won’t end up leaving you with dead bats in your roof/ceiling, which is not environmentally beneficial you need to take a few important things about bats into consideration.

  • Don’t do a bat exclusion during winter as you will never be sure that bats did migrate or not, also you can’t tell if all of them do go out in the evenings even if you see some leaving their roots when doing your evening “Bat watch” during the winter season
    • Excluding bats during their breeding season is unacceptable, bat pups during
  • this time remain behind when parents go out to forage for food and if you install the none return valve on the entry/exit points, parents won’t be able to get back to their young ones and eventually they will die.
  • Installing an exclusion valve during the weaning is unethical, like any other creature out there, bat pups also grow at a different rate from each other. If you do a bat exclusion during the weaning stage, less developed bat pups will be trapped inside the roost and will die when parents no longer have access to feed them


    • You may exclude bats anytime except during the hibernation, breeding and weaning season. Bats are long lived and have a slow reproductive rate which means drastic population declines such as those caused by unacceptable methods used within the pest control industry may be difficult for bats to recover from.

    Roles played by bats in our environment

    Insectivorous bats play a significant role in controlling insects around us including those that are agricultural, forest and disease spreading pests which results in reduction of pesticide use. Some plants depend solely on fruit bats for flower pollination and seed dispersal.

    Below here are a few steps to take if you want to do an environmentally friendly bat exclusion or eviction.

    STEP 1: First identify all entry/exit points bats use, preferably by using the “bat watch” technique. All the entry/exit points you will identify will require a none return valve that will allow bats to leave the roost site at dusk as usual but not be able to crawl back in

    STEP 2: Take note of all gaps that need be sealed, large or small all-round the building to ensure no gap will be left that bats may potentially use to gain access into their historical roost site in future

    STEP 3: Since its imperative to provide bats with an alternative roost site even though it’s not a hundred percent guaranteed that they will use a bat house, google for places that sell bat boxes/houses near you and get yourself one.

    STEP 4: If It’s not the winter season, breeding season or weaning stage you may carry on and seal all the that bats may potentially utilize in future all-round the house using building material.

    STEP 5: Install your bat house exclusion valves/ none return valves on all entry points identified during bat watch. It’s advisable to install you bat house weeks or months prior to doing your bat exclusion.

    STEP 6: Wait for seven to ten days before removing the none return valves. Perform another bat watch to confirm that all bats are out, if they are then you can remove the none return valves and seal the entry/exit points

    Note that insectivorous bat rarely fly out if it’s raining as rain interferes with their echolocation. If it’s raining or too cold leave the none return valves in place until the weather is conducive enough for bats to leave their roost site.

    See a picture of an example of a none return valve.

    See figure below for an example of a bat box.