is sex a need ????................?

[........]

I'm just tryin to figure it out.
I've heard people refer to the act of intercourse as "fulfilling a need"
I know its not THAT kind of need (like food or water)....
And I know its a need in the sense of humanity continuing

BUT.....is it like a biological need individual wise.
Is it true that sometimes you "NEED to get laid"..or stuff like that?

If you understand what I'm asking, please explain.

thanks