The retail giant continues to use other robots in its stores, including autonomous floor scrubbers.
Missing inventory is a problem for retailers, because sales can be affected if shoppers cannot find a product on store shelves.
Online challenge
A precise inventory is also essential for Walmart’s increasingly popular pickup and delivery services.
The company posted a massive $137.7bn (£107bn) in revenue last quarter, driven higher by a 97% surge across its e-commerce platforms during Covid-19 restrictions.
With competition among retailers fierce, other companies have taken different approaches to automation.
Online retailers such as Amazon and Alibaba have tried to drive efficiency by using robots at their warehouses.
Amazon bought a robotics company in 2012 to drive efficiency in its fulfilment centres, where it now uses more than 200,000 robots.
Walmart’s bricks-and-mortar rival Target has been more reluctant to use robots in its stores, preferring instead for customers to interact with humans.