Swatting is a reflex. It’s also useless. Flies see in slow motion. Their compound eyes process movement five times faster than yours. That fly isn’t dodging you; it’s just bored. Instead, use patience. Move slow. Think like a ninja.
Pro tip: clap your hands over the fly, not at it. They panic and fly up. If you clap above them, you trap them. This works exactly 8% of the time. That’s 8% better than failure.