Actually you don't technically help them mate, you just make a strain that can't reproduce via hermaphrodites self-fertilizing. You keep the males from being out-bred that way.

C. elegans has male and hermaphrodite sexes, not male and female. The hermaphrodites self-fertilize slowly to produce a few hundred hermaphrodite offspring, while mating with a male gives them many times as many offspring with half being male. But the lab-bred males are so bad at mating that even if you have a population that's half male, they get massively outbred by the hermaphr... (read more)