Topic: heroin rats
In one experiment, scientists studied rats who had been given regular doses of heroin. Some of the rats were taken to a new area and given a larger dose of heroin. The others were injected with the larger dose, but kept in their regular environment. The mortality rate of the rats injected in a new environment was twice that of the rats injected in the familiar environment. No similar experiment of human drug users would be conscionable, but a survey of the survivors of heroin overdoses found that seven out of ten were in a new place when they overdosed.