"I don't think it's here anymore," a father says to his young son as they walk past the Milwaukee Public Museum's "Bison Hunt on Horseback" diorama, which depicts buffalo attempting to escape Native American hunters in pursuit.

They walk around the bison exhibit and back into the North American area without experiencing the thrill. But they're not alone. A lot of people think the snake button isn't there anymore.

The snake button is a Milwaukee secret, like the Safe House password. You just know about it. While the old lady in the rocking chair on "The Streets of Old Milwaukee" remains a frightening sight, nothing thrills quite like pressing that little button.

Two moms with three kids walk out of the new "Scenes of the Dinosaurs" exhibit and right up to the far side of the second-floor diorama and press the snake button for what seems like an eternity. Gleaming joyfully at having made the snake rattle, it's clear that the old-school snake button remains one of the museum's greatest attractions.

Although MPM management won't want to hear it, no new innovation, cool interactive exhibit or brilliant addition to the IMAX can match the simple pleasure of the snake button. It may be one of Milwaukee's worst-kept secrets but, since 1966, it's been one of its best-loved charms.

The rattle activated by the button hidden among the rocks -- the genuine article shed from the tail of a live rattlesnake -- has drawn visitors from across the globe. According to museum security officer Gloria Gott, a Japanese couple in 1990 made a pilgrimage to Milwaukee and the museum just to rattle the snake.

"I'll never know how they found out about it," says Gott. "This couple stopped me right at the door and asked in broken English where the button was that made the snake go."

Museum maintenance technician Paul Dorobialski had a rare encounter during his first childhood experience with the snake.

"I got thrown out looking for that button," says Dorobialski. "It was probably 1971. My older brother wouldn't tell me where the button was, and I probably got a little out of hand crawling all over looking for it. A very big security guard escorted me to the door."

Renee Romfoe of St. Francis and her 3-and-a-half-year-old daughter Maddy walk up to the exhibit, take a sharp right and head directly to the corner. Maddy knows where the button is, but still fumbles around to find it. Knowledge of the "secret" button has been passed down from mother to daughter and youngsters relish in the accomplishment of making something move.

"I remember it from when I was a kid," a father says as his stepson Tyler presses the noisemaker again and again and again. "I told my stepson about it since I enjoyed it so much."

"It's a Milwaukee thing, and funny it's never where you remember it being. It's quite beautiful that so many kids know how to find the button," recalls Matt Kirchner, a father of two from Whitefish Bay. "I showed our oldest, Noah, the general area and he figured it out. Then, he was able to show his younger sister Sarah. Both of our kids love showing their secret to others."

So don't give up. The snake button is still there -- and it's as fun as ever, even after nearly 40 years.