Mayfly: only lives for a few hours to a day, as they mate, lay eggs, and die.
Drone ant: lives for only a few weeks, during which they mate with the queen and then die.
Gastrotrich: a microscopic aquatic animal that lives for just a few days.
Housefly: typically lives for only a few weeks, as they rapidly mature and reproduce.
Gall midge: a tiny fly that lives for just a few days as they mate, lay eggs, and die.
Ephemeral plant: germinates, flowers, and produces seeds within a few days, and then dies.
Culex mosquito: the male mosquito typically lives for only a few days, while the female mosquito lives for a few weeks to a month.
Adult may beetles: also known as June bugs, they live for only a few weeks, during which they mate and lay eggs.
Pacific salmon: after swimming upstream to spawn, they die within a few weeks.