Walmart’s shelf-scanning robots have been on the move. In the four months since the company announced it was deploying them in 50 of its stores, the automated (and vaguely llama-looking) machines have traveled nearly 2,000 miles through the aisles.

Keeping busy: John Crecelius, Walmart’s vice president of innovation, says the robots have been scanning the food and consumables sections of the stores three times a day. They search for out-of-stock items, incorrect prices, and other things that need an associate’s attention. In total, the robots have scanned about 78 million items.

By the numbers: Back-of-the-envelope math suggests about 13,000 scans per robot per day.

In the field: Walmart has deployed bots in geographies with varying traffic and characteristics. “In these first 50 stores our focus has largely been getting [the robot] to be a product that makes a meaningful difference,” says Crecelius. The company plans to continue to collect data before considering an expansion of the program.

The reaction: Martin Hitch, the chief business officer of the robots’ manufacturer, Bossa Nova, says customer reaction has been mixed. While some shoppers are intrigued by the robots, at least 50 percent completely ignore them.