Little black flies

[PStarfish]

My mare has soaked hay and this afternoon when I removed her soaking net from the bath, hundreds of small black flies flew off it. I then went to do her stable and removed the net from last night which still had some hay in the bottom and again, tons of these little midgy things flew up in my face! I discarded the old stuff but can't chuck a whole new net. I assume that the heat we had today is a factor but I was a bit grossed out. Do you think they will cause any harm to the hay? And what, if anything can I do about them? I can't cover the hay while it's soaking, and have to leave it hanging once drained as she's brought in by the yard. Hay has to be soaked else she gets a cough,plus it's really helped with her weight this year. Yucky things!!

 

[HappyHooves]

I expect they will be a kind of fruit fly - you get lots around fruit bowls in summer, and also sugar beet if its left long in warm weather. They are attracted to the sugars and the soaking water has lots in. You need to make sure that you refresh the water each day and scrub off the starch/sugar that deposits on the inside of the soaking vessel. You could always cut a plastic feed sack open and lay the sheet over the soaking haynets. You would be better to hang the hay up for as soon as possible before eating as the moulds and spores will multiply once the soaked hay starts to dry out - never use dried but soaked hay.