BERKELEY, Calif. — Come lunchtime on the campus of the University of California, Berkeley, thousands of students rush out for a bite to eat and head back to class. But for more than a year, a few hundred have stayed put and instead summoned a knee-high robot bearing a burrito, a burger or other meals from a nearby restaurant.

The robot invasion is underway, and the intruders are bringing hot pizza.

Kiwi Campus, a start-up that operates in the square mile surrounding the university, has made more than 60,000 robotic food deliveries in the past two years. “There’s nowhere in the world that robots are a more integral part of its sidewalks than Berkeley,” said Sasha Iatsenia, Kiwi’s head of product. “It’s ultimately a social experiment to see how robots get accepted by a community.”

The company takes a trial-and-error approach. The path followed by each robot at first was guided entirely by remote control by Kiwi employees 3,800 miles away in Medellín, Colombia. So-called pilots, still in Colombia, where the founders are from, now set and adjust a series of way points along a path. The delivery bot is about the size of a proverbial breadbasket, and it carries a single cubic foot of cargo.