Bats flying around your home can be an unsettling experience. If you’ve discovered these winged creatures roosting in your attic or walls, you probably want them gone as soon as possible. But before taking action, it helps to understand bat behavior and biology.
Read on to learn how long bats can survive in a home environment.
If you’re short on time, here’s the quick answer: Bats can potentially live inside your home for several months if they find suitable roosting spots and food sources.
Why Bats Enter Houses
Looking for Shelter
Bats frequently sneak into houses because they are seeking refuge and a place to roost. As seasons change, bats migrate and search for warm, protected spots to spend their winters. Attics, walls, and other crevices in human homes often resemble the caves and tree hollows where bats would traditionally hibernate.
An opening as small as a quarter-inch crack is enough for a bat to squeeze through and enter a home.
In the summer months as well, female bats that are pregnant or nursing baby bats require safe spaces to birth and raise their young. They tend to gather in maternity colonies, where a group of females live together.
The warm spaces and plentiful insects found around houses make them appealing roosts for reproducing bats. According to bat conservation organizations, a single brown bat can eat over 1,000 mosquito-sized insects in just one hour! Access to this bounty of bugs attracts maternal bats to attics and walls.
Access to Food Sources
Bats’ appetite for insects explains another major reason why they slip into residences. Houses tend to have an abundance of flies, moths, mosquitoes, and other tasty arthropods that bats naturally prey upon. Outdoor bats are accustomed to feeding on whatever insects are available seasonally.
But homes have a more constant supply of bugs thanks to light fixtures that lure them in at night, crumbs and spills that accumulate, moist areas, and access points to the outdoors.
Bats are also drawn to the sweet scent of ripe or fermented fruit. They follow aromas wafting from kitchens or fruit bowls that have been left out too long. A bat detects food particles from up to two feet away using echoes and noise pulses.
Their sharp sense of smell combined with ultrasonic echo perception allows bats to adeptly locate even trace sources of enticing food inside homes.
How Long Bats Can Survive Indoors
Suitable Roosts Allow Months of Occupation
Bats that find their way into homes can potentially survive for months if the conditions are right. They are highly adaptable creatures and able to take advantage of man-made structures as roosting spots.
Attics, eaves, walls, and unused chimneys often provide bats with protection from the elements and a place to rest in between feeding.
As long as the indoor temperatures are suitable and prey is available nearby, bats may continue living in a building undetected for weeks or months. Species like big brown bats are especially suited for roosting in houses because they can squeeze through tiny gaps to gain access.
Once inside, they roost in dark, secluded areas that mimic the caves and tree hollows they would otherwise occupy.
Availability of Food and Water
Access to food and water are key requirements for bats to persist living indoors. Most house-dwelling species are insectivores, feasting on moths, mosquitoes, beetles and other flying bugs. As long as prey remains available through open windows and doors or other small openings, bats can continue to hunt and return to their roosts nightly.
Some bats may also utilize attic pools or piped water as drinking sources. Leaky faucets or overflow drainage can provide the fresh water bats need to survive if they don’t have ready access to outdoor waterways.
Bats in Hibernation Mode
Bats that take up residence in human dwellings during their active spring and summer seasons may continue staying into the winter if suitable hibernation spots are available. Attics with pockets of higher temperature and humidity can create perfect overwintering sites.
Hibernating bats congregate in clusters and enter a torpid state. Their heart rates and metabolism slow dramatically. This allows them to survive for up to 6 months on stored fat reserves until warm weather returns in the spring.
A single disturbance can wake a bat and cause it to burn through 2 weeks worth of stored energy.
Bats are more vulnerable during hibernation. If awoken repeatedly or unable to safely re-enter hibernation, they risk starvation and death. This makes winter bat control delicate – eviction should only be done after hibernation ends to avoid endangering them.
Getting Bats Out of Your House
Exclusion is the Best Method
The most effective and humane way to evict bats is through exclusion, which seals off entry points so they can’t return (The Humane Society). This involves:
- Inspecting the house at dusk to observe where bats exit
- Waiting until young bats can fly from late spring through summer
- Sealing cracks and holes with foam, caulk, hardware cloth after bats leave at night
Exclusion allows bats to find alternative shelter without harming mothers and pups that cannot fly. Once entry points are sealed, bats will look elsewhere (65% success rate for solving issues long-term) (CDC).
Avoid Poisons and Traps
Methods like poisons, chemicals, and traps are not recommended for removing bats from homes. Reasons to avoid these techniques include:
| Poisons | Can be absorbed into walls/floors and harm people |
| Glue boards | Inhumane, bats die slowly when stuck |
| Ultrasonic repellers | Not proven to effectively repel bats |
The goal should be to get bats out safely without using threats. Killing bats is also discouraged since they eat tons of insects nightly, providing free pest control!
Professional Bat Removal
For severe infestations, professionals use effective and ethical exclusion methods. They also ensure bats exit before sealing entryways. Prices range from $300-$1,200 depending on the house size and colony size (This Old House).
To find an experienced contractor, check industry sites like the National Wildlife Control Operators Association. Members adhere to codes of ethics for resolving human-wildlife conflicts.
With some clever DIY exclusion techniques and a little patience, bats don’t have to be permanent houseguests. And avoiding harm to these extraordinary creatures means we can continue benefiting from their astonishing insect consumption and pollination abilities!
Preventing Future Bat Invasions
Seal Up Entry Points
Bats can squeeze through incredibly small spaces to gain access to attics or other sheltered areas in houses. According to the CDC, even an opening less than a half-inch wide can allow a bat entry. Sealing up any cracks, holes, gaps, or other openings can help prevent bats from getting back into a house where they have roosted previously.
Some of the most common potential entry points that should be sealed include openings around chimneys, vents, windows, doors, and spaces under eaves or attic vents. High-quality caulk, weatherstripping foam, stainless steel wool, or copper mesh can be used to plug gaps.
Make sure to seal up openings both on the inside and outside of the house for maximum effectiveness. Completely excluding all bats from reentering improves prevention as well as safety.
Install One-Way Exclusion Devices
One-way exclusion devices, such as tubes or cones with flaps that let bats out but prevent them from re-entering, can be extremely useful additions to sealing up cracks and crevices. According to Bat Conservation International, these gadgets cause minimal disruption to bats already roosting while preventing them from returning.
The devices should be installed at dusk, when bats have left to feed. The bats will then still be able to exit but won’t find their way back in. For best results, the one-way devices should be left in place for 5-7 nights and then removed and any remaining holes sealed.
Using one-way exclusion prevents bats from becoming trapped inside and dying. This humane method stops bats from reentering once they find a new roost.
Conclusion
While having bats roosting in your home may only last for a season, their presence can be disruptive and raise health concerns. By understanding bat behavior patterns and using proper exclusion methods, you can humanely remove bats and prevent future colonies from taking up residence in your house.
