hahahahhaha, that made my night. there are multitudes of limiting factors that control populations, and only recently (on the geologic scale) have humans become advanced enough to thwart most of the natural controls. Think about any population of animals that doesn't have much contact with humans; over the long run, their population is fairly steady.
sure there are population surges, but then predator populations increase, there is a food shortage, or disease etc causes a die off and the population returns to a sustainable level. Lemmings actually release chemicals into their own bloodstream when they become overpopulated, and much of the population dies. this is why you often hear of huge amounts of lemmings running off of cliffs.