I will probably continue to have the biological urge to reproduce right up until my menopause.

They were slaves of their own chemistry, following a blind biological urge.

I learned, first time out on patrol, that nothing hikes up that old biological urge like being shot at and living through it.

There's almost a biological urge to want your child to be pre-eminent, and to shelter him from setbacks.

Still, that had never been love, not as she understood the term; it was a biological urge.

She told herself she was just feeling a biological urge.

Sometimes I think love is just a biological urge.

'And you expect me to give in to it, to some biological urge?'

I inherited my father's biological urge to garden.

No matter what faith they are, everybody hates dark days; there's almost a biological urge to celebrate the return of light.