Chemicals like DDT interfered with the reproductive cycle of raptors. The poison built up in the falcons’ bodies as they ate birds that, in turn, had eaten insects and plants contaminated with the chemicals. The result was diminished fertility, plus eggs with shells so thin, they broke under the parent’s weight.

How are animals hurt by DDT?

DDT affects the central nervous system of insects and other animals. This results in hyperactivity, paralysis and death. DDT also affects eggshell production in birds and the endocrine system of most animals. DDT has a very high tenancy towards biomagnification.

Why did DDT kill birds?

The birds’ brains contained concentrations of DDE, a breakdown product of DDT, ranging from 155 to 1,043 parts per million, with an average of 552. … Populations of bald eagles and other birds crashed when DDT thinned their eggs, killing their embryos.