Suicide flies

These flies, about a quarter to one-half inch in length, are often found flitting about clumsily in swarms during the spring and autumn months of warm & damp climates. Mated pairs bond together at the abdomen & link for the rest of their brief lives. The female is twice the size of the male & is the one that flies forward after bonding. The most notable trait of these flies is that they are absolutely fearless, and will even fly right into the mouth of a predator, or an unwilling and unsuspecting person who walks through one of their swarms. Suicide flies can detect exhaled breath, and are quite willing to be eaten. It is only after being eaten or crushed that the larval forms can emerge. The adults lack useful mouth parts for eating, and may only drink water. The larvae are omnivorous & can eat nearly anything organic. After bonding, both of a pair generate a chemical in their bodies that makes them sweet and very tasty, & gives a soft red hue to their underbellies. Unbonded, they just taste like bugs. Pupae taste like bitter dirt. Should a mated pair go uneaten (or unsquished) the larvae are not released from their egg casings & will eventually starve along with their parents. Once eaten, the egg casings can survive being chewed and survive the passage through the stomach. In larger animals—certainly anything cat-size or bigger—they hatch inside the intestine & devourer the partly digested food found there. Eventually they pupate and are excreted. Smaller predators: toads, mice, spiders, other insects, don't have such an easy time as unwitting hosts. For these creatures the tiny white grubby dots of larvae will eventually consume much of their host before pupation. After months of living within a host, they form tough chrysalises & transform into the flying adults. In the event that a mated pair of suicide flies is crushed—underfoot or by a flyswatter, for example—the larvae are still released. It is much more difficult for them to find food, but they can survive on plant life and the organic matter in the soil.