The days of the human warehouse worker are numbered. Across the U.S., distribution centers are rolling out giant robot systems to automate the packing, stacking, and sending process as much as possible. Symbotic, a company behind one such system, thinks that the next five years will transform the industry.

The system is easy enough to understand. When a package arrives, a driver uses a forklift to move the goods towards a robot arm, which unpacks the boxes and places the individual products on a conveyor belt. The products are scanned and sent to specially-designed storage units, kitted out with robots that take the incoming packages and find shelf space. These tiny buildings aren’t for humans: the robots whizz around at around 25 miles an hour, and the aisles are less than three feet wide.

Those in the business believe that machines like these are the future. “In the long run, if you don’t automate, eventually it will really limit your supply chain,” Norman Leonhardt, head of sales for Witron, a company that makes factory automation systems, told the Wall Street Journal. “America is moving towards it. There aren’t enough young people coming into the workforce who really want to work in warehouses.”

These machines are also beating the humans when it comes to organization. Take an automated grocery wholesaler. When a package is ready to go to a store, the robots can move goods out of the storage center and arrange them into the perfect pallets, tailor made for the design of the destination grocery store.

There is an argument that these machines will lead to mass unemployment, and without a system like universal basic income in place, it could lead to widespread poverty. But in the case of Kroger, which uses a Witron automation system, bosses argued that the staff simply don’t exist.

“Twenty-five, 30 years ago, there were a lot of folks who made careers working in warehouses,” Frank Bruni, Kroger vice president of supply chain operations, told the Wall Street Journal. “Today I don’t think that dynamic exists as much.”

Watch a similar system, the Kiva robots that whizz around Amazon’s distribution centers, in action:

Correction 9/22 8.40 ET: An earlier version of this article referred to a company called Symbiotic. The correct spelling is Symbotic.