leopard geckos are determined by temps.
If the eggs are incubated at a temperature of 79F, virtually all of the offspring will be female. At a temperature of 85F, one can expect more or less equal ratios of males and females. At 90F, the great majority of the hatchlings will be males. At 92F, the hatchlings are virtually all males.
i usally set my incubator at 85F for an equal mix of both sexes when i breed my leos