The Roomba wasn't the first machine iRobot had in the works. In fact, at the company's headquarters in Massachusetts, all the flawed prototypes reside in a secret vault of old bots—mechanized ideas that never came to fruition.

In the above video, Nancy Dussault Smith, iRobot's VP of marketing and communications, takes you on a tour of the facility. She shows off things like a climbing robot, a rover for working in nuclear plants, and a creepy doll with eyes that can move around. Unfortunately, iRobot no longer makes toys, but you'll get a peep at some of the playthings it used to make. You'll also see founder Colin Angle's first robot, as well robots that didn't make it past the experimental phase. From the looks of it, the machines aren't taking over anytime soon. Or are they?

Here are some highlights of the 25-minute tour:

Inside iRobot's Vault of Failed Experimental RobotsS

Here's one capable of being emotionally responsive, thanks to an expressive set of eyebrows.

Inside iRobot's Vault of Failed Experimental RobotsS

This baby doll fakes real human emotions.

Inside iRobot's Vault of Failed Experimental RobotsS

This toy dinosaur with touch sensors knows how it's being played with, so it can repsond accordingly.

Inside iRobot's Vault of Failed Experimental RobotsS

This crab-like robot borrows in the earth on a hunt for mines.

[IEEE Spectrum]