Stinky bats

SheffieldLass · #1 (**permalink**) 19-03-2010, 01:06 AM

I've finally discovered what the bad smell in my bathroom is ... bat urine and thick layer of droppings in the insulation in the roof space above. It really is stinky ....

I'm not sure when the bats use my roof, whether they are there at the moment, or are summer visitors, though when I inspected the roof space in the summer there didn't seem to be the stink that there is now. They appear to use a space between the sarking and roof tiles judging by the mess down the wall inside the roof space and access it through the roofspace, via a hole under the chimney flashings, I think.

Anyway the worst affected insulation has been removed and I'm going to have to decide what sort of insulation I need to replace it with. Whether encapsulated stuff or foil backed boards, as I don't want more urine soaked stuff stinking the place out.

The roofspace is also full of flies which find their way into my house by the dozens each day (well today there were hundreds trying to get out of my bedroom windows - that was a bit too much

). They did seem to be clustered more in the area that the bat droppings are. Do bat droppings encourage flies?

I do like bats, just hadn't realised how smelly they can be, or what a mess they can make. I guess I'm just going to have to learn to live with them and try to minimise the effects of their mess.

The Woodman · #2 (**permalink**) 19-03-2010, 08:45 AM

The good news is that you've discovered the cause of the smell!

I would ask you to consider getting some help with your situation.

Have a look at this website first Bat Conservation Trust

and then give the Bat Helpline a ring on 0845 1300 228 and explain the situation to them. Request a visit from a licenced bat warden who will assess the problem with a home visit. The whole service is free and will cost you nothing. Natural England (BCT are their contractors) provide this service for householders who, without advice, may inadvertantly or otherwise, could break the law. I'm sure you will be aware, bats and their roosting habitats are protected by law and it is quite possible to sort the problem out without recourse to disturbing or destroying a bat roost. That's the heavy bit out of the way.

From what they find, NE will give you the best advice on how to conserve the bats you have and manage the droppings and urine without detriment to your health and sanity.

During this spell of warmer weather bats are coming out of hibernation and returning to their regular roosts. For example, it could be that the droppings are from a seasonal nursery roost which has been present for a number of years. Depending on what type of roost is above your bathroom, occupancy times will be explained to you by the bat warden.

Droppings and urine are easily managed but it is important to get advice on how to and what time of year to do it. It is critical that nursery roosts are not disturbed due to the chance of mothers abandoning their pups.

The Soprano Pipistrelle Pipistrellus pygmaeus is a likely contender for your roost as they do have a distinctive smell. However, the smell could be caused by the natural breakdown of droppings and evaporation of urine. You will probably need to install a non permeable membrane e.g. plastic sheet to prevent the potential of urine soaking into the plaster of the bathroom ceiling but there's one important thing to consider if this is recommended. To prevent urine from "pooling" on the surface of the plastic, it is when it does this that it takes much longer to evaporate and therefore the chance of smelling increases, put a fibrous material on top of the plastic. Let the urine drop onto a piece of fibreglass insulation or capillary matting. It won't soak in but will dissapate by capillary action and dry very quickly.

Your flies are probably nothing to do with the bats. Again, the bat warden should be able to identify the flies and suggest the reason they are there. It may be that they are Cluster Flies and happen to like the environmental conditions in the void for hibernation or perhaps blow flies hastening the decay of a dead bat.

Help is available, it will not cost you anything and hopefully you will get good advice to enable you to enjoy your bats for many years.

Have a look at the Bat Conservation Trust website and get involved in their colony count survey!

The Woodman · #3 (**permalink**) 19-03-2010, 10:12 AM

OK - perhaps you haven't discovered the cause of the smell after all!

Poor wording on my part and hopefully the rest of the text may help.

mycoranger · #4 (**permalink**) 19-03-2010, 05:55 PM

Bat poo does not smell unless there is a problem with damp in the loft and if that is the case the bats leave. Nor do bat droppings attract flies, like The Woodman said they are most likely cluster flies which have nothing to do with bats other than they share the same liking for living in roof spaces. If you have flies I would suggest speaking to a reputable pest controller for advice but be sure to tell him/her that you have bats in the loft.

From your description of the loft I would, like The Woodman, hazard a guess that you have a reasonably large summer maternity roost of Soprano Pipistrelle. Soprano pips have a unique musky smell which, when you have a large roost, can permeate the house. Do you live in Scotland because up here we do get large, smelly, Soprano roosts? Summer roosts of 1-3,000 are not uncommon in my area.

Nor do you have to live with the mess there are ways and means of accomodating both bats and people in the same house without causing hassle to either. but you do need someone to have a look for you so get onto the bat helpline and get it sorted out before the bats return for the summer.

thunder · #5 (**permalink**) 19-03-2010, 10:20 PM

Quote.
Bat poo does not smell unless there is a problem with damp in the loft and if that is the case the bats leave.
Endquote

That is not quite true. Bat droppings do not usually smell, but if they get damp (because of little ventilation in the space) then they do smwll, and that won't necessarily make the bats move.

Quote
Nor do bat droppings attract flies, like The Woodman said they are most likely cluster flies which have nothing to do with bats other than they share the same liking for living in roof spaces. If you have flies I would suggest speaking to a reputable pest controller for advice but be sure to tell him/her that you have bats in the loft.
Endquote

If you have cluster flies, it is pointless contacting a pest controller, as there is nothing they can do about them. Cluster flies only confuse them.

henrya

SheffieldLass · #6 (**permalink**) 19-03-2010, 10:21 PM

Thanks, Woodman and Mycoranger.

The flies do appear to be Cluster Flies. It seems that my neighbours also have problems, which is not surprising given that we are a small hamlet surrounded by extensive forest and arable land. I've just got two more holes to fill in between the roofspace and habitable rooms where pipes have recently been removed, so hopefully they will exit by the route/routes that the bats use, and won't come into my rooms in nuisance numbers. Apparently they do also have a smell, but not like a gent's urinal which is the dominant one here, but they could be adding an overtone.

I've recently had a partial rewire and a replumb, and all the tanks and pipes up there have been removed. I don't think the electrician or plumber got caught short up there .... The plumber did manage to knock over an almost empty tank, which did wet the insulation, but that has been dry a few weeks. It was in the area of the bats droppings. The smell is definitely of urine though ...

I will contact the Bat Helpline. I'm interested to see what bats they are, and how many, and when they are here. I think there has been a roost for many years. This insulation was intalled in 1995, and underneath was 1 inch insulation, and there were signs of completely disintegrated droppings on that, in that area, but not in other parts of the roofspace. And also a small amount between that and the plasterboard ceiling.

I do need to put in an airbrick or two as the roofspace is not ventilated, and it needs ventilation for construction purposes, particularly as the insulation is about to be increased to current standards. I'll find out what permissions I need.

I do believe in sharing my house with wildlife, though there are limits ... I have to admit I'm not too keen on sharing my habitable rooms with 100s of flies .. a few are ok ... I'm sure the bats and I can live in harmony, once I've found a good way to manage their waste products ....

My other roof space which doesn't have bats or flies but does get over-wintering field mice. I was going to use one of those plug-in ultra sound devices in the autumn to discourage them (as they had virtually destroyed the pipe insulation, though they had left the electrics alone). But that could well have implications for the bats, even though the roofspaces are completely separate. Not sure how far the sound travels. I guess that also depends on when the bats use the space too. There may not be a bat presence then, anyway.

SheffieldLass · #7 (**permalink**) 19-03-2010, 10:28 PM

Quote:

Originally Posted by thunder

Quote.
Bat poo does not smell unless there is a problem with damp in the loft and if that is the case the bats leave.
Endquote

That is not quite true. Bat droppings do not usually smell, but if they get damp (because of little ventilation in the space) then they do smwll, and that won't necessarily make the bats move.

henrya

My earlier post crossed with yours ... well, yes the roof space does need ventilation. And the bathroom ceiling does not have a vapour barrier, so water vapour will permeate through the ceiling. Sods law that it is the bathroom beneath the area of concentrated droppings ...

I've also read that the bats' urine is the smell that upsets people most ... I imagine that like humans' urine it will continue to smell long after it was deposited ...

SheffieldLass · #8 (**permalink**) 19-03-2010, 10:45 PM

Quote:

Originally Posted by thunder

If you have cluster flies, it is pointless contacting a pest controller, as there is nothing they can do about them. Cluster flies only confuse them.

henrya

From what I've read, they leave a pheromone, which attracts the next autumn's population to take up residence. And not a lot you can do about that ... The pest control people can only kill the ones that have taken up residence. It won't stop them coming back in following years. So I think trying to make the ceiling between my first floor rooms and roofspace flyproof is the most effective method of nuisance reduction ...

thunder · #9 (**permalink**) 19-03-2010, 11:37 PM

Quote:

Originally Posted by SheffieldLass

From what I've read, they leave a pheromone, which attracts the next autumn's population to take up residence. And not a lot you can do about that ... The pest control people can only kill the ones that have taken up residence. It won't stop them coming back in following years. So I think trying to make the ceiling between my first floor rooms and roofspace flyproof is the most effective method of nuisance reduction ...

That is quite right about the pheromone. They don't do amy harm at all, so blocking up the holes that they use to get from roofspace to bedrooms is much the best solution. Les scrupulous pest controllers will spray them and tell you they have solved the problem, without mentioning they will be back.

henrya

thunder · #10 (**permalink**) 19-03-2010, 11:39 PM

Quote:

Originally Posted by SheffieldLass

My earlier post crossed with yours ... well, yes the roof space does need ventilation. And the bathroom ceiling does not have a vapour barrier, so water vapour will permeate through the ceiling. Sods law that it is the bathroom beneath the area of concentrated droppings ...

I've also read that the bats' urine is the smell that upsets people most ... I imagine that like humans' urine it will continue to smell long after it was deposited ...

There should be deodorisers that will help mask the smell that will not affect the bats.

henrya