[Nails]

Can any one tell me if mossi larva in water is harmful to my chooks, the water butts are filled up every week with fresh water but there always seems to be larva in it, is there any thing i can do or put in the water to stop it?

[pigeonpie]

I'm not sure if there are any risks but I try to make sure the girls have fresh water daily and clean out their drinkers at least once a week.  However, every time I water the plant pots or spill any other water in the garden they go absolutely nuts and crowd around to sip up every last spot, supping from the top of the plantpots as the water is absorbed, almost licking the paving or ground to get every last drop.  They also drink from anything that is left around no matter how gross it looks and how many things are floating in it.
I guess no one has told them that they should drink fresh water.
My black lab also prefers dirty water to anything out of the tap.

[Ice]

Try a few drops of citronella oil or ordinary oil.  This breaks the surface tension so they can't breed.  But beware, oil can go rancid.

I doubt the larvae are harmful.

[Aunt Sally]

Are your water butts covered ?

Mosquitoes must get in to the surface of the water to lay their eggs.