Will fly spray kill a mouse?

Fly spray is typically not effective in killing mice. Fly sprays usually contain pyrethroids, which are insecticides that affect insects by attacking their nervous systems.

Mice, being mammals, have different physiological systems and are less susceptible to the toxins commonly found in fly sprays. While a direct hit to the eyes or ingestion of a considerable amount of fly spray might irritate, harm, or potentially even kill a mouse, fly spray isn't reliable means of eliminating mice infestations