Gnats dancing

There's usually a swarm of gnats by my garden gate in the late afternoon at this time of year. If you move towards them, they move away and then go back to where they were when you've gone past. The swarm can be from 60-70 cm to a metre wide. I've often wondered why they dance just there, and what for, so today I did a bit of research.

They're winter gnats (Trichocera annulata), about 8mm. If you look at them closely they're like tiny crane flies. Apparently it's the males who dance like this, to attract females, who must be lurking somewhere nearby, sussing the boys out. They lay their eggs in damp places with rotting vegetation, and the larvae hatch out in the spring.

I haven't been able to find out why they seem to have a favourite spot, like my gate, but it can be a tree branch or a fence post. They're so fast and the dance goes on for ages, they must use a lot of energy. They feed on vegetation and fungi. There's plenty of both in my garden.

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