Question: I have a problem with large numbers of small flies in my house. Can you tell me what they are and how to get rid of them? They are easy enough to catch, but there are many more each day. They are mainly in the bathroom so I wondered whether they are attracted to water.
Answer: Thank you for sending your insect image into the Discovery Centre at Melbourne Museum for identification. The flies in your bathroom are from the family Psychodidae and are commonly known as bathroom flies, moth flies or drain flies.
These dark grey flies are 2-4mm in length and have hairy moth-like wings. They have a jerky flight and are observed around bathrooms, in damp subfloors, in greenhouses and in other locations where moisture and the presence of decaying organic matter will support their presence.
If you are seeing large numbers and you don’t regularly leave your windows open, the flies must be breeding inside your house or in your water pipes. You could have a drainage problem, such as slow-draining pipes, or water pooling in over-watered pot plants. Once you remove all permanent sources of water and fix any drainage issues, the flies should disappear.
Bathroom flies are not harmful to people and will not damage clothes or linen. They are therefore considered to be of nuisance value only.
Hi Mia. We think that the infosheet above should give you the information you're asking about. These flies are called drain or bathroom flies. They breed in water, so you may have an drainage problem that you need to fix, rather than using pesticides. If this doesn't work you might wish to contact a professional pest controller. The insects are not harmful to people or clothes.
We can definitely have a go at identifying your flies, but we would need at least an image of them first, if not a specimen. Should you be able to capture and image or specimen, please feel free to lodge an identification request with the Discovery Centre here. Once we know what they are, we can then offer information about their behaviour.
In answer to your question, bathroom flies do not turn into worms. Once the flies pass through their larval stage and emerge as adult flies that is the form they retain until they die. Even if you managed to ingest a bathroom fly I doubt that one fly would do you any harm.
Shane - Museum Victoria offers a free identification for insect species. Requests can be lodged at this part of the website. If you can't provide a clear photograph you'll need to send a well-protected specimen via the post. See these guidelines for further info. Hope this helps!
Hi Jeanette, Museum Victoria has a free identification service. If you are able to collect some of the flies you can either bring them in, or post them in and we will have the entomologist take a look for you. Unfortunately we cannot offer advice about pest control, but once you know what they are you may be able to make some simple changes at home to eradicate them. Information about the identification service can be found here: http://museumvictoria.com.au/discoverycentre/ask-us-a-question/identifications/identification-guidelines-/
Please see the answer given on 22 Sep 2009.
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