The fly below was spotted in Tasmania. It's a sheep nasal bot fly, which was introduced (much to the joy of the sheep) into Australia. Though they prefer sheep, there are many cases where they've infected humans. Infected, you ask? Here's what I mean:
The adult female fly is active during summer and early fall. Eggs are retained in the body until they hatch. Flies deposit as many as 500 larvae in the nostrils of sheep. The larvae then move up the nasal passages to the nasal and frontal sinuses. The larvae remain in the sinuses for 8 to 10 months and then are sneezed out of the nostrils. The larvae pupate in the soil with the pupal period lasting 3 or more weeks, depending on temperature. Adults then emerge from the pupae and may live as long as 28 days.
Isn't nature lovely sometimes?