Like any good science story, this one is about a person who asked the sorts of questions no one else was asking. Unlike most science stories, though, the answers to those questions involved rooster testicles.

The scientist in question was Arnold Albert Berthold and, back in 1848, he wanted to know more about hormones. His question was this: Can glands — in this case, testes — that secrete a mysterious substance (testosterone) work, regardless of where the glands are in the body?

Up to this point, most people believed that hormones moved along tiny nerves — or other physical pathways — to get from one part of the body to another. But Berthold had other ideas.

“[Berthold] took a bunch of roosters in his backyard, he castrated some, and he saw ... they were not chasing hens anymore,” says Randi Hutter Epstein, author of the book "Aroused: The History of Hormones and How they Control Just About Everything." “They got fat and lazy.”

But Berthold wasn’t done.

“He took a testicle from one of his roosters and implanted it into the belly of another castrated rooster,” Epstein said. “So picture this if you actually want to: Here was this rooster with nothing between its drumsticks and yet a lone testicle floating within the loops of its intestines.”

And Berthold saw an enormous change in the rooster. Its comb got redder, and its interest in hens perked back up. Berthold discovered that hormones don’t need veins to travel along. Indeed, they can move from one place to another, even if the original transmitter has been disrupted.

“Today, when we're sending emails and connecting to specific people across the globe, we think that chemicals that have specific targets is no big deal. It's a huge deal,” Epstein says. “I like to consider hormones your internal WiFi. I actually don't understand how the internet works or how I send emails, but I do understand hormones. I like the analogy. I know that there's routers in my house to help with the WiFi. We have chemicals in our body that work like routers.”

And Epstein says: hormones affect so many things in our lives.

Take, for example, leptin, a hormone that is supposed to rise after eating so that you feel full. But people with a leptin defect are constantly hungry, which could lead to higher calorie consumption and weight gain.

Hormones have played a role in history too. During a sensationalized murder trial in the 1920s, when Nathan Leopold and Richard Loeb were tried for killing a young family friend, errant hormones became a defense. On the surface, both young men seemed normal.

But their lawyer, Clarence Darrow, brought in a team of doctors to examine Leopold and Loeb. The findings showed major hormonal problems with both of the boys.

“One of the boys had a harden pineal gland,” says Epstein. “We now know that the gland in your brain has to do with your circadian rhythms — sleep and wake. But at the time people thought it had to do with morality and inhibitions. The other boy had polyglandular syndrome. Basically it means he had a lot of things wrong.”

But even though we now have an advanced understanding of hormones, Epstein says most people don’t give them much thought. Why? Because we associate them with mostly with puberty and pregnancy.

“We tend to focus on these huge bodily changes, like girls getting breasts, and boys changing, and puberty and all the physical changes,” Epstein says. “We grow up hearing, ‘It's your hormones; don't worry your body's changing. I know you feel awful about yourself. It's just your hormones.’ So we tend to have these blinders on of what our hormones are.”