A "mega den" of as many as 2,000 rattlesnakes can now be viewed online thanks to a round-the-clock webcam.
Not everybody will be glued to the footage - but it is expected to be a must-watch for scientists and other snake enthusiasts who are helping to broaden understanding of these unusual reptiles.
The remote site on private land in northern Colorado is on a hillside full of rock crevices where the snakes can keep warm and hide from predators.
"This is a big, big den for rattlesnakes. This is one of the biggest ones we know of," said Emily Taylor, of California Polytechnic State University and head of Project RattleCam.
The exact location is being kept secret to discourage snake lovers - or haters - from messing with the animals.
This time of year, only pregnant female snakes are at the den while males and other females move into the lower country nearby.
In August, the babies will be born.
They are called pups and, unlike nearly all other reptiles, they do not hatch from eggs but are born alive.
Also, unlike other snakes, rattlesnake mothers care for their young, protecting them against predators and shielding them with their bodies.
Sometimes rattlesnakes even care for the young of others.
"Rattlesnakes are actually really good mothers. People don't know that," Taylor said.
She also said rattlesnakes get a "bum rap as creepy and threatening", but the webcam shows they are social animals that don't go out of their way to be aggressive.
"I try to speak up for the underdog and to show people that rattlesnakes have this other side that's really worthy of our admiration," she added.