Loads of tiny flies in downstairs loo

[LoyaltyBonus]

They've been there a few days now. I've had the fly spray out and there are lots of dead ones but new ones must be hatching from somewhere too. Literally 100s of them

They do seem to be confined to the loo, despite the door often being left open they haven't invaded the rest of the house. The loo is clean (honest) and there are no nooks and crannies for anything to be lurking in, it's basically a cupboard under the stairs!

So where are they coming from, they're like tiny fruit flies, the kind you get if you leave fruit out in summer.

I think there’s a thing called drain flies. Google will probably have a solution.

They will be coming out the sink. Flush lots of hot water down there regularly for a few day’s and keep the plug in inbetween.

www.doyourownpestcontrol.com/drainflies.htm

Lots of ideas here

oh and do the same with the overflow hole and cover it as well.

Water leak somewhere possibly

Ah, that makes sense, thank you

We had this when I was young and we moved to a new house. god I was terrified of the downstairs loo.

In our case it turned out the builder hadn’t attached the toilet to the drain so all the waste had just gone under the house

Put a few kettles of boiling water down the sink and toilet, and a cup of cider vinegar and washing up liquid
Water should kill the eggs and the vinegar and liquid will trap and kill the alive flies

I had fruit flies last month, and Google said leave out a dish with vinegar and a dash of washing-up liquid (to break the surface tension) I got loads of drowned dead ones.