Not a fly on the wall...
Rodent and rabbit bot flies develop as parasites of mammals. Adult flies lay their eggs near the entrance of rabbit or rodent burrows or runways and other sites frequented by their animal hosts. The eggs hatch in response to the warmth of a potential host and the maggots enter natural openings, such as the nose or mouth. Initial development usually occurs at these areas but later migrate. Ultimately they settle under the skin in sites typical of the
species (neck, abdomen) and as they grow they appear as large swellings known as warbles.
Larval development within the host animal typically takes 3-5 weeks in small rodents and about two months in jackrabbits. When full-grown they exit the animal and burrow into the soil where they pupate within 24 hours. (Pupae are black with spines.) If temperatures allow, pupation may only take about a month, allowing a second generation to be produced. Often, pupation requires a considerably longer period and is the life stage in which bot flies survive winter.
Adults emerge in morning. Males usually perch on vegetation where they can get a good range of vision and pursue passing females for mating. Mating occurs in flight and adults live only about two weeks.