Dick In A Haystack 

It's when you are the only dude in a room full of hot chicks.
You are more likely to get laid, when you have the only swinging dick around.

Dude, did you hear? Evan got laid by three different chicks last night at the same time. How the fuck does that happen? He was the only dude left after the party. Like a dick in a haystack...of vaginas.

Dick In A Haystack by Gay4Ghosts July 2, 2018

Needle in a Haystack 

Usually used when someone's trying to do the impossible.

It's also used when you're coding

Needle in a haystack coding example:
strpos("haystack", "needle");

Needle in a Haystack by ihfsdihaoifd September 21, 2021

Needle in a haystack (literally) 

When a needle is impossible to find because it’s in a stack of hay

“there’s a needle in a haystack (literally)

Needle in a haystack (literally) by ImMaker37 June 28, 2023

finding a needle in a haystack 

When you need to do something that is really hard, almost impossible

They were on the bleachers.
Looking for then was like finding a needle in a haystack.

finding a needle in a haystack by Conrado41 March 14, 2017