Bats in my attic...

[Seeking Hobbes]

In my quest to tick off home projects, I decided to tackle the attic which needed... cleaning, new fans, better insulation, screening, etc., etc.

When I got into the attic, I found that a family of bats had moved in. They made their home behind a gable vent and where some screening had torn its way into the attic.

In all I counted three bats and a baby... before they scurried either out of eyesight (baby and one adult) or into the attic behind some boxes (remaining two adults).

They didn't bother me while I was working in the attic & mainly stayed out of sight, content with squeaking/screeching their displeasure with my company. (clearly, the bats were female)

Any ideas how to deal with them?

(Note)
- I'm a big fan of bats... just not in my attic. In fact I was thinking of installing bat houses in my back yard to help with the mosquitoes.

- As I get older, I've become much more of a "live & let live" person. I regularly catch & release the frogs/snakes in my pool skimmer. So I'd hate to kill the bats just to get them out of the attic.

 

[Nemo2]

Garlic worked on Count Dracula.

But this link may help you:

http://www.humanewildlifecontrol.com/wildlife-issues/bats.html

 

[MichaelB]

One way to deal with bats is to find and seal the holes around the roof where they enter except the one they use. When they fly out at dusk to hunt for food, cover that hole so they cannot get back in. They fly away looking for another home.

For bigger problems the pros use a flexible screen-type material that is attached all along the length of the roof. They tape it to the side of the house. When the bats leave they encounter the mesh and have to crawl down the side of the house to get out and fly off to hunt, and went they return the mesh prevents them from entering, so they look for another place to nest.

Are you sure there are only a few?

 

[braumeister]

Another source of information. from the Bat Conservation people:

Bat Exclusion Instructions

Learn what you should know about excluding bats from your home or building with this free download.

Dealing with Unwanted Guests (pdf)

 

[Seeking Hobbes]

Thanks, this is great information...

My dilemma is that I've seen a bat "pup," no bigger than a vienna sausage, crawling up the screen. It was kinda cute, in a batty sort of way.

What about baby bats?
Bats often roost in buildings during maternity peri- ods, when they give birth and raise their pups. Exclusions should not take place until young bats are able to fly; otherwise, they will be trapped inside, away from their mothers, and die of starvation. Separating pups from their mothers may also lead mother bats to search for other entrances to reach their young.
In North America, the maternity season begins as early as mid-April in the southernmost United States and in mid-June in the northern U.S. and Canada. Young bats are flying by late August. Exclusions should not be conducted between April and late August.

Since they don't recommend disturbing them before the pup learns to fly... I suppose I'll monitor the situation and try to work around them. I may also try to segregate that part of the attic from the rest; without spooking the mother & baby too much.

At least now I know that if I build a bat house or two... they should get used.

 

[MBAustin]

My family's summer lake home has had "bats in the belfry" for as long as I can remember (kindergarten?). It's a 100 year old house with lots of opportunities for critters, and bats don't need much of an opportunity. Honestly, we don't mind them in the attic so much, it's that they are attracted to the more human-occupied parts of the house, especially the bedrooms right under the attic. Not fun to be dive-bombed by a bat at 0-dark-30, especially when you know that a small percentage are rabid.

Every few years we have someone come in and (re)seal up all the entry points. The chimney flashing has been a big issue. It's an unusual summer when we don't have a few appearances in the house.

We like their mosquito eating, so hopefully they will like your bat houses. We should have thought of that 50 years ago!

 

[Accidental Retiree]

After 30+ years in this house, 2 weeks ago I saw a bat flutter through my backyard. I thought was pretty amazing!

 

[Midpack]

If they aren't doing any damage, I'd just leave them alone. I'd they're damaging the house, I'd go with MichaelB's suggestion. Exterminators would be my last choice.

It's interesting how people react. Most if not all of us have mice and other visitors that we never see, without issue. I told a co-worker this at work years ago and she was first 'no way, not in my house' and then 'horrified' when she realized I was most likely right...most "pests" are way more afraid of us than vv. When they get defensive it's usually because they're cornered/trapped and/or they are defending a nest/babies. If it's the latter, I let the nursing run it's course and then block them off when they depart (and they will) on their own.

 

[Nemo2]

If they aren't doing any damage, I'd just leave them alone.

From the link I provided upthread:

If inhaled, bat droppings can cause histoplasmosis, which is characterized by flu-like symptoms. The very young, very old and those with impaired immune systems are at greatest risk for severe illness.

 

[Midpack]

If they aren't doing any damage, I'd just leave them alone.

From the link I provided upthread: If inhaled, bat droppings can cause histoplasmosis, which is characterized by flu-like symptoms. The very young, very old and those with impaired immune systems are at greatest risk for severe illness.

Your link begins with discussion on having a bat fly into your house, a completely different situation than in your attic. Also from your link

If bats move in As bats lose their natural roosts in trees and caves, they are sometimes forced to seek shelter in human-made structures. There is little reason to evict these highly beneficial animals unless they are causing a problem or are considered a nuisance. Bats should, however, be prevented from entering human living quarters.

Where bats roost in buildings Bats may roost in attics, soffits, louvers, chimneys and porches; under siding, eaves, roof tiles or shingles; and behind shutters.

Histoplasmosis is also caused by bird droppings, something we're all exposed to daily, though not in our living quarters. YMMV

Indiana is part of the eastern and central United States where exposure and infection are prevalent. In 2000, 82 confirmed cases were reported for a crude incidence rate of 1.35 per 100,000 population. [from all sources, not just bats]

 

[tryan]

I dealt with a colony of 50-75 in my attic. Drape nylon screen over the hole where they exit. Bats are too clumsy in flight to fly UNDER the screen. So it creates a one-way gate. Then seal the hole after verifying none have exited (watch early evening -7:30-8pm) meaning they're out.

Problem I had is that they attempt to take-up residency elsewhere in the same house. Takes some persistence to get them to leave for another house. Most of the colony moved to the chimney then to another opening under the roof. Still have a few in the barn so I put a bat house on the barn ... not occupied yet.

We average 1-2 in the house per year. Never "kill" ... just catch and release. I clean 4-5 fried dead ones from the chimney every year. But they're not in the attic.

The poop and urine are toxic ... really do not want this stuff piling up in your attic. Not to mention 10% of them carry rabies ... Like mice, if you see 1 there are 10 others. You saw 3-4 ... I'ld expect 20-30 will pour out the that hole ... watch for it at dusk.

 

[Nemo2]

Your link begins with discussion on having a bat fly into your house, a completely different situation than in your attic.

From the top of the same link:

Property Damage from Bats

• Bats commonly reside in building walls, attics or between the roof and the ceiling. Droppings and dead bats can cause severe odour, damage and contamination of property and heating/AC systems, which makes removing bats from a house all the more important

FACT: Bat colonies can range in size from one to several hundred.

• The longer a bat stays in a building, the greater the chances of breeding and infiltrating smaller spaces in turn making removing bats from a house more difficult. Proper removal and cleanup may eventually involve ripping out drywall, sheathing and flooring.

FACT: Bat colonies double in size every year. Bats in Ontario tend to hibernate or go back to the same property every year unless they are removed and excluded properly. They do not typically fly south for the winter and tend to roost and hibernate in places with a moderate temperature (i.e. buildings).

 

[Seeking Hobbes]

There's some great info here...

As for my situation... I think I'm only dealing with a a handful of critters, though from the collection of guano inside under the gable vent, they've been there for generations. (probably since the old vent fan died)

I have to competing goals...

... to allow the bat family to live; raising their pup into a mosquito eating champ.
... to complete the "projects" in the attic (installing new roof mounted attic fan, repairing the vent screen, cleaning & sorting through old boxes, adding insulation)

My plan is to continue with the projects... doing my best not to disturb the family.
When I get to repairing the screen and cleaning out the boxes closest to the (nest?) I'll wait until evening when, hopefully, they will be out feeding.

If I scare them off during the process, sobeit; I figure that i did my best to accommodate them.

 

[Midpack]

Sounds like a very good plan, best of luck...

 

[PaddyMac]

Thank you for looking out for the pup. Wish more homeowners were as good natured. Best of luck.