Walmart recently announced adding thousands of robots to its stores. It expects autonomous floor scrubbers in 1,860 of its more than 4,700 US stores by next February and will have robots that scan shelf inventory at 350 stores. There will also be bots at 1,700 stores that scan boxes as they come off trucks and sort them by department onto conveyer belts.

Walmart claims these ‘smart assistants’ will reduce the amount of time workers spend on ‘repeatable, predictable and manual’ tasks in stores and allow them to switch to selling merchandise to shoppers and other customer service roles, according to a release by Walmart.

Bots will lift sales and make stores more efficient, the retailer feels. Walmart also says bots limit worker turnover. That’s because it’s hard to consistently find workers to unload trucks and keep up stores overnight. Walmart has been testing this technology in hundreds of stores over the past year. Walmart plans to bring 16-foot-tall pickup towers—automated vending machines that quickly fetch customers’ online orders—to 900 new stores this year. Walmart is adding robots to help it manage rising costs, including for store labour.

Walmart’s 920-pound self-driving floor scrubbers, called the ‘Auto-C’, use automated technology to navigate custom routes around the store and mop up the floors. The machine relies on sensors to scan for people and aisles. Walmart tested it at 360 stores before deciding to roll it out to an additional 1,500 locations.