The main reason to see gnats and drain flies in bathroom is the moisture and dampness around your bathtub and shower screen.
Gnats in bathroom drains.
Having gnats in your sink drains can be a real nuisance to live with but luckily eliminating them is a fairly easy task.
Drain flies are small measuring an eighth of an inch which is about the size of a fruit fly or a gnat it s easy to confuse them as a matter of fact.
The gnats most likely to occur in sinks and sink drains include fruit flies moth flies and to a lesser degree phorid flies.
The breeding and developmental sites for these small flies often called sink gnats are varied but for the most part include habitats that stay moist and contain decomposing waste components.
Identify the problem areas.
Any area with multiple drain flies is likely a problem.
The main reason you might find gnats and drain flies in the bathroom is from the dampness and moisture that can be found around your bathtub and shower and your air conditioner vents.
Examine all the drains in your home and any area inside or outside the home that has standing water.
Before you can effectively kill bathroom gnats you need to determine what is bringing them into your home.
Luckily drain flies do not stray far from the place they have chosen to make their home so it is rare for a drain fly infestation to spread to all areas of the house.
This is the second largest source for gnats to multiply and increase the population with all the necessary conditions required to breed.
Since drain gnats are attracted to moist areas that are rich in nutrient rich organic material septic tanks sewers and the drains in your home make the perfect habitat and breeding grounds for these types of gnats making it necessary to find ways to scare flies away by eliminating their food and breeding sources.
Gnats required dampness and moisture to breed and multiply.