For a whale of a good time, size does matter!

Scientists have discovered that male narwhals use their horns as “sexual weapons” to lure the ladies — with frisky females preferring to hook up with large-tusked mates, according to research published Wednesday.

“The information that the tusk communicates is simple: ‘I am bigger than you,’ ” lead researcher Zackary Graham told the UK Metro.

A blubbery beau flashes its massive tusk — actually an extension of a tooth — to fight off other males and ultimately impress potential mates, according to Graham and other researchers at Arizona State University’s School of life Sciences.

The Scientists came to the, well, horny conclusion after they analyzed 35 years of tusk data from 245 adult male narwhals. They say when it comes to mating frequently, big horns are “one of the most charismatic structures in biology,” according to the study.

“The narwhal tusk is a sexually selected signal that is used during male-male tusking contests,” Graham said.

The research also showed that so-called “tusking” — in which two narwhals rub their horns together — is linked to frequent sexual activity.

The study found that the animals can sport tusks up to 8 feet long.

Graham hopes researchers will employ aerial and aquatic drones to allow even greater insights into narwhal behavior.

In the past, studies have shown that the sea creatures spend most of their lives hidden under the Arctic ice, leading researchers to believe their tusks were used only for hunting and fighting.

Graham said his interest in how animals select a mate led him and his team to the discovery.

“Broadly, I’m interested in sexual selection, which is responsible for creating some of the craziest traits in biology.

“As an evolutionary biologist, I try to understand why some animals have these bizarre traits and why some don’t,” he said.

“One way we try to understand these traits is by looking at the morphology, or the size and shape of them.

“I immediately became obsessed with trying to think of some interesting animals to study.

“ I was Googling everything; maybe I can find a dinosaur in a museum. Eventually, I found the narwhal tusk.”