Why are flies so hard to shoot?

Flies are difficult to take pictures, mainly because they have compound eyes. Its time resolution and field of vision are much higher than those of human eyes.

The resolution of compound eye is limited by the image point, generally speaking, its resolution is lower than that of human eye. But its time resolution is 10 times higher than that of human. The human eye can distinguish 24 pictures per second (which is also the lowest speed of animation). The compound eye of insects can reach about 240. The field of vision of compound eyes is relatively large (this can also be obtained through our daily experience of flapping flies, and flies will fly faster no matter which direction we start from).