Glowing sperm go head to head in fight to be the daddy

She can exercise what's known as cryptic female choice, giving some sperm an advantage over others.

Inside this fruit fly reproductive tract, a battle is taking place – a battle of sperm. In turquoise are the sperm of Drosophila simulans; in orangey-red are those of the closely related Drosophila mauritiana.

Females of species are promiscuous...

She will get the sperm of many males then give certain sperms advantages over other sperms

rivalry in the animal kingdom starts well before conception.

SnF
If only for the brilliant title. Are the sperm from London ?
Who's the daddy is a term we use a lot

Cody