Four years ago, iRobot co-founder Helen Greiner stepped down from the company she helped turn into an all-important supplier of the military's growing arsenal of ground robots. Now today, she's unveiled the first 'bots to roll off her new company's assembly line. What are they? Teeny tiny hovering drones, designed to fly through your window and spy on you.

That's just one of two robots revealed so far from Massachusetts company CyPhy Works, founded by Greiner after leaving iRobot. We've also now got a sense of what Greiner's been developing for the past couple of years.

The first is Ease, or "Extreme Access System for Entry." Really, it's a tiny hover-bot designed for "intelligence, surveillance, and reconnaissance." And it's small enough – it only has a 1-foot diameter and a height of 16 inches from top to bottom – to fly through windows and maneuver through buildings with its ducted fan engine. In a video released by the company, the Ease can be seen hovering through an abandoned-looking building to a psychedelic funk soundtrack. It can also theoretically stay in the air forever.

"Being able to stay up aloft without constant interruptions to come down and recharge is a critical new capability," Greiner tells Danger Room. "And with locations where you don't have a lot of infrastructure."

The reason is that instead of communicating wirelessly, the drone receives instructions and power through a microfilament cord of spooled copper the width of a fishing line and connected to the robot's ground control station. And because it's plugged in directly, the Ease drone should be harder to hack than other drones.

Once launched, a single battery at the ground station can also keep the drone up for 50 minutes, but this could be extended indefinitely by hot-swapping batteries at the control station. And as it is, most small drones that go wireless can't stay up for very long, because "people have [started] putting more and more sensors and payloads onto them," Greiner says, which drags on the power supply.

And while the operators are swapping out the batteries, Ease is scanning everything it sees with two high-def cameras and a third, albeit optional, thermal camera. Another purported advantage of the microfilament line is that the operator doesn't have to worry about losing a wireless signal, say, if the robot moves behind a brick wall. And since the drone is moving in potentially close quarters to obstacles and people, "you really want to make it safe" by using a ducted fan, she says.

The other new drone is the Parc, or "Persistent Aerial Reconnaissance and Communications." Like Ease, it also hovers. But the Parc is designed to fly high and for long periods of time, and resembles a flying bug with four skinny legs and a quadrotor. The robot can hover at 1,000 feet while being powered – like the Ease – by a microfilament line.

And while it's up there, Parc can carry out "persistent stare capabilities" for up to 12 hours at a time (on one battery) while packing two cameras, one in high-def and another in thermal. And it has night vision and "flies itself." (Oh great.) The military is reportedly interested.

There's no word if CyPhy Works has received any orders yet, though. These drones are still prototypes. But it's probably not far off. The Boston Globe's Scott Kirsner estimated the company's investor funding at $3 million, "much of it from Cambridge-based [venture capital] firm General Catalyst." But Kirsner also notes that the company has received millions more in federal grants. Which could make those tiny hover 'bots begin flying into houses and spying on you from above sometime soon.