No, don't try to clean your monitor screen... The tiny spots you see in the photo are not dirt on the glass, they are hundreds if not thousands of little mayflies.
Mayflies (also known as Canadian soldiers in the United States, or shadflies or fishflies in Canada and Michigan; also up-winged flies in the United Kingdom ) are aquatic insects belonging to the order Ephemeroptera. This order is part of an ancient group of insects termed the Palaeoptera, which also contains dragonflies and damselflies.
Over 3,000 species of mayfly are known worldwide, grouped into over 400 genera in 42 families. Mayflies are relatively primitive insects and exhibit a number of ancestral traits that were probably present in the first flying insects, such as long tails and wings that do not fold flat over the abdomen. Their immature stages are aquatic fresh water forms (called "naiads" or "nymphs").
They are unique among insect orders in having a fully winged terrestrial adult stage, the subimago, which moults into a sexually mature adult, the imago. Mayflies "hatch" (emerge as adults) from spring to autumn, not necessarily in May, in enormous numbers. Seeing lots of mayflies in the Darebin Parklands close to where we live is good news as their presence indicates a clean, unpolluted environment!
This post is part of the Skywatch Friday meme,
and also part of the Friday Photo Journal meme,
and also part of the Weekend Green meme.