Many are highly variable, sometimes producing small, infertile males that superficially resemble females.

S. daguerrei only produce winged virgin queens and males.

The result was a strain that would produce slow-feathering males and fast-feathering females.

When mated, females avoid the fecundation of some eggs to produce males.

Why are they producing males and females in more or less equal numbers, which they are?

The females can be workers or soldiers, and cannot produce workers but instead produce males only.

Cattle produce males (bulls) and females (cows) at the same rate as humans, pretty much 50/50.

The aim of the system was to produce physically and morally strong males to serve in the Spartan army.

The colony grows progressively larger and at some point will begin to produce males and new queens.

Matings of a male and hermaphrodite will produce both males and hermaphrodites.