When Andy Rubin was replaced by Sundar Pichai as head of Android and Chrome, many thought that he’d be leaving the company for pastures new. But now, it’s been revealed that in fact, he’s been be working on something much bigger inside Google’s secret labs.

Rubin is now heading up Google’s robotics arm, according to an article in the New York Times.  Earlier this year, the search giant quietly acquired seven technology companies in the hopes of creating the next generation of robots.

But what could Google want with robots?  One idea that’s been mooted is delivery robots, an idea that’s arguably much more feasible than Amazon’s delivery drones.  And with Google already offering local deliveries from retailers such as Target, Walgreens, and American Eagle Outfitter in San Francisco, there’s every reason to think that, one day, robots could be knocking on your door with your purchases instead of people.

Google’s robots could also replace do away with the need for humans in warehouses to do all the heavy lifting.

“The opportunity is massive,” said Andrew McAfee, a principal research scientist at the M.I.T. Center for Digital Business, to the New York Times. “There are still people who walk around in factories and pick things up in distribution centers and work in the back rooms of grocery stores.”

Some of Google’s key acquisitions this year include Waze, the crowdsourcing navigation service; Flutter, a company that builds gesture recognition technology; and Wavii, a natural language processing firm. All these technologies could be incorporated in Google’s bots to help them navigate the streets whilst delivering packages, and to interact with customers.

But there could be more to Google’s robotic dreams than just delivering packages. Recently, a number of technology firms have been building robots with security in mind, such as Knightscope’s K5 Autonomous Data Machine that aims to replace security guards, and Linda, a robot designed for care homes that alerts staff if an elderly person has fallen. What with its mountain of cash, Google’s robotic ambitions could lead to the creation of all kinds of robots that would make our lives safer and more secure. Google bots could roam around the city, patrolling crime hotspots and quickly alert authorities of any mishaps, or they could be posted outside schools to guard kids.

As McAfee stated, the opportunity is massive, but Google is keeping its lips sealed as to what it really has in mind with its robots. Let’s just hope it isn’t secretly planning to use its bots to spy on people or collect more data from them – we’ve had quite enough of that, thank you Google!