Flies attracted to light reflection

[ruthandsam]

Just noticed a strange thing happening with a couple of pesky flies in our front room. Every time light was reflected onto the wall from my son's watch, the flies followed the light. We tested them many times by firstly keeping still, they just hovered. Then reflected the sunlight from the watch in exaggerated patterns on the wall - and guess what, the flies followed in exactly the same pattern. Quite a circus act! Any information to support this would be welcome (sad I know!!!) ...............x

[rov1200]

When I have occasion to go into our darkened loft and switch on the light flies appear from the recesses and hover round the light bulb.

During this heatwave when out in the countryside and woods flies seem attracted to the body sweat.

These diseased ridden species should be swatted and killed at every opportunity.

[Wak]

Hence the expression, "Time Flies"?

[jomifl]

They can't see where they are going in a dark loft so presumably resort to walking.