Nor need DDT imperil wildlife. The destruction that Carson described was caused by the agricultural use of DDT as a mass insecticide in vast quantities on crops. But the discriminating application of DDT indoors involves only a tiny, contained, environmentally tolerable, reversible fraction of the dose. That is why some international health (as opposed to environmental) agencies, including Unicef, still support the judicious use of DTT. Even the WHO is now softening its stance.