Bat: Confused by porch light?

Something odd happened to me last night.
I had taken a break from working and was sitting on my screened-in porch reading “The Amber Spyglass” (the third book in the “His Dark Materials” trilogy upon which the new “The Golden Compass” movie is based).
This was about three in the morning.

Anyway…
As I was reading the book I heard something pretty heavy fly into the window about six feet away from me.
I looked up and saw what looked like a large bat clinging to the screen outside.
I got up to walk over to it, to get a better look, and it dropped off the screen as I got closer.
I looked around a bit, through the window, but didn’t see anything, so I sat back down with my book.
A few minutes later I heard the “bat” flapping around down by the bushes under the window, and beating its wings against the outside porch wall.
I heard a high-pitched squeak, so I was pretty sure it was a bat at this point.
It was moving along the wall towards the corner of the house away from me, as it kept beating its wings against the wall.
It turned the corner, where the front door is, and kept beating and moving until it was beating on the front door and screeching.
This bat seemed to be trying to get into the house – onto the porch I was reading on.
It was the oddest thing.
It beat on the front door for a good four or five minutes.
I thought maybe it was confused somehow, by the lights – I had no idea – so I turned the porch light off and went to get a flashlight.
When I got back the bat wasn’t making any more noise.
I went outside with the flashlight and looked around, but saw nothing.
I turned the porch light back on, and went back to finish my book, and it never came back.

I think it was a bat.
Is this odd behavior for bats?
I recently moved to a new house, and where I used to live, you really wouldn't see bats any larger than palm-sized fruit bats, so I have little experience with them.

 

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Perhaps it just wanted to read along with you and wanted to join you. It just couldn't adjust his landing in time.

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Remember he was there before you.

 

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So how are those books?

Oh, and er...doesn't every artificial light mess with the systems of nocturnal creatures?

 

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I have seen bats who are attracted to lights at night because they feed on insects attracted to the lights. Could that be the reason, do you think?

 

Possibly, but I wouldn't be so sure.
Before people settled here it was nothing more than mounatins, a bunch of lakes and thick forest.
People building barns and raising livestock could very well have been what the bats needed to thrive.

 

Very good.
There were a few things I was was a bit disappointed in, but overall very well written, and I highly recommend them.
I got them as a gift from a friend of mine about 4 years ago, when we were discussing the concept of the book series I am working on, and I let her read a bit of it.
She said she was reminded of these books.
I put them on a shelf, not wanting to read them until after I finished my books, but when I saw the movie was coming out I wanted to read them before seeing it.

I would assume it does, but the way he seemed to be frantic and trying to get into the house was the odd part to me.

 

That sounds pretty reasonable.

 

They zoom around the street lights eating bugs here.

 

It was obviously Count Dracula

 

Few possibilities:

Bat migration may be starting (I dont know where you are located) and this guy hadnt encountered windows, and was confused by screen / window combination.

The wing beating without taking off is unusual behavior. Bat could have injured itself. The only time I have seen bats flapping wings without taking off was young learning to fly and too scared to let go. Its too late in the year for much of that going on.

Bat is sick with some kind of ear infection or other infection, screwing up its sonar so it cant hear itself. It could also be someone tried to rid their home of bats and tried to poison this guy.

Bat has rabies and is very sick. Rabies has been found this year in some bats locally.

From your description, I would lean towards a sick/poisoned bat.

 

Maybe it's sonar can't detect the screen material.

 

it wants your blood

 

I bet it was injured. Bats aren't that strongly build to begin with, and from your description i can tell it hit the window pretty hard. If birds fly into windows they sometimes act in a similar way because they are dazed and confused by hitting their head. It dont think it wanted to get into your house, it merely looked that way.
It may eventually have regained full consciousness and flew away, or it may have crawled away into some bushed to die.
Anyway its a weird story.

 

When I was a graduate student, one hot summer with windows open and no screens a bat did fly into the room, where I and my two room-mates were studing. I just watched. One, a little drunk tried to catch it. The third, a law student said put a light in the window and turn the others out. (I thought that silly but it worked almost immediately.) He said he had read a story where that was done.

 

Hmm so they fly towards the light?

 

Perhaps, but certainly that is not proved by this happening. Perhaps the light only aided it find the window and escape from the drunk room-mate chasing it.

 

Sort of, in an indirect way. Just as you and Orleander mentioned, they've learned to associate lights with flying insects. When I was much younger, I used to enjoy playing a game of "bat fishing." Stand under one of those security lights, tie a line around a small, rough pebble (about an inch in diameter) and toss it upwards toward the light. On about every 10th throw or so, you'll pull in a bat. Release it and toss some more.

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(They won't be hurt.)

 

I am building a house, slowly all by myself. Often I am not posting on Monday or Tuesday as spend two days out of Sao Paulo working on it, if no rain is forcast. (Wife teaches at university on those two days most of the day.)

As it will be many years yet before I am done, I have slightly slanting (one cinder block difference) flat concrete roof on a section now that will ultimately be a third floor storage space. The true roof will only be one block higher at the edge and thus the space near the edge will not be very useful. I want to make an interior wall on the temp roof (concrete storage space floor) near this one block high perimeter wall and divide the space between these two low walls into small chambers to use the space between these two low walls as homes for either birds or bats (Both eaters of insects) or both.

Does anyone know how to attract bats to live in these small chambers (or a reason why I should not do this)? I know that mosqueto eating martins like to live in colony homes and that the size of a US quarter is correct for the hole they enter, but know nothing about what bats like, except that the real roof should some hooks hanging down for them to hang from when sleeping. Perhaps I should put some Xmas tree lights (under volted to last for ever) under the real roof overhang?

 

Bat urine and feces stink really really bad and can cause damage. You would be better off figuring out a bat house outside of the home.

http://www.ianrpubs.unl.edu/epublic/pages/publicationD.jsp?publicationId=654

http://www.ianrpubs.unl.edu/epublic/live/g1575/build/g1575.pdf

Be sure to roughen up the inside good so they can grip it or they will reject it. Hooks hanging down is not appropriate. Something with the texture of rough cut wood would be more attractive. Or the rough texture cedar siding type of cut. Hope that makes sense.

 

to mlweed:

Thanks for your two references. One also lead me to www.batcon.org which is very good source of information.

I will read up on histoplasmosis (caused by fungus that can grow in bat and bird droppings in humid condition)

My house overlooks a large water reservoir which is also used for hydro power so water level varies a lot and there are often small wet spots near edge for mosquitoes to breed in. I am up about 100 meters higher than the high water level on a hillside - part of a pensula sticking out into the lake with water view extending around 270 degrees. There are several mosquito born diseases in Brazil and plenty of mosquitoes even 100 meters above the lake when there is no wind so I remain interested in getting some bats in my chambers which will have concrete floors. I do not think either noise or odor will be a problem thru the slightly sloping concrete that will serve as my roof for years (until I get around to building the more highly sloped roof.)

I already plan a roof rain water recovery system to flush toilets and water the garden. Now I am toying with the idea of built in hose that can flush out the guano from the bat chamber floors and direct it into the garden water system. Perhaps the bats will both eliminate the need to use insecticide in the garden and fertilize it from me with zero labor to distribute it.

One thing your reference made me understand is the bats would not want me to divide up the space into small rooms as the Martins do. Perhaps both ends of the small, low, edge-of-house, under-roof, concrete-floored, chamber will be for Martins and between the end bird houses one large bat house. (Birds hunt in daylight and bats at night - team work against insects and both produce fertilizer, transported by water to the garden.)

My house is my own design with many "crazy" ideas built in. I am having fun building it, too frugal to pay to work-out in a gym but mixing concrete and lifting blocks, lots of climbing up and down (I am doing it all alone -no one to hand things up) is good exercise and it get me out into the clean air of the reservoir area instead of polluted Sao Paulo. It will have long "lap lane" swimming pool and that water circulates thru roots in a long gravel bed of vegetation and thru cascade of small water falls for filtration on one side of the draw-bridge entrance walkway, which passes thru a two story high bird cage entrance passage leading to the front door to mention just one of the "crazy" parts of my plan. (The water fall terminates in a fish pond and then goes thru sand filter to return to the lap lane pool. - no chlorine filter for me or the fish - all natural filtration.)

A wind mill pumps the water - sticking out on the pensula 100 meters above the lake, there usually is enough wind to keep the water flowing and well aerated for the fish. As the wind power available and water pump power required both go as the cube of their respective velocities, the source and load stay perfectly matched for all wind speeds. I.e. a simple vertical shaft directly drives the water pump - a non-electric system.