(ANN ARBOR, Mich.) (AP) — Robot food delivery is no longer the stuff of science fiction. But you may not see it in your neighborhood anytime soon.

Hundreds of little robots __ knee-high and able to hold around four large pizzas __ are now navigating college campuses and even some city sidewalks in the U.S., the U.K. and elsewhere. While robots were being tested in limited numbers before the coronavirus hit, the companies building them say pandemic-related labor shortages and a growing preference for contactless delivery have accelerated their deployment.

“We saw demand for robot usage just go through the ceiling,” said Alastair Westgarth, the CEO of Starship Technologies, which recently completed its 2 millionth delivery. “I think demand was always there, but it was brought forward by the pandemic effect.”