While they eat, the blowflies lay eggs in the softer parts of the body, and these hatch into maggots twenty-four hours later. These maggots attract other insects, like the predatory rove beetle, who feast on them. And so on. Wave after wave of hungry insects arrive, marking time as accurately as a clock. Meanwhile, the blowflies follow their natural life cycle.
Maggots become pupae, the pupae become adults.
By surveying the insects in and around a corpse, forensic scientists can help a police investigator determine how long ago a victim was murdered.