A robot in Japan learned the hard way that children can be cruel bullies, IEEE Spectrum reports.

During an experiment, Japanese researchers let a Robovie 2 robot roam around a shopping center in Osaka. The robot was programmed to politely ask humans to step aside if they got in its way. If the human didn't, the robot would go in the opposite direction.

Some children, being pranksters, took this as an invitation to mess with the robot. They intentionally blocked its way, or formed a ring around it so it didn't know what to do. This seems like pretty harmless fun, but some kids took it a step further, shaking, punching, and even kicking the robot.

Of course, you could argue that the children knew it was just a machine and that it didn't exactly have feelings. But as a follow-up, the researchers interviewed the children about their behavior. Half of them answered that they believed their actions were "stressful or painful" for the robot, IEEE Spectrum reports. It seems the children ascribed human-like feelings to the robot, and then decided to bully it anyway.

The bullying got so bad during the experiment that researchers had to program an "abuse-evading" algorithm for the robot. When the robot approached a human, it would see whether that person was under 4 feet 6 inches — kids. If there wasn't a significant density of taller people around — i.e., adult supervision — the robot would flee toward grownups.

This maneuver may work in a crowded shopping mall, where there are social pressures to stop grownups from beating up robots. But we can't forget what happened to hitchBOT, a robot that just wanted to see the world. It was destroyed by vandals and left for dead on the side of the road in Philadelphia last week.

"I guess sometimes bad things happen to good robots!" a hitchBOT Facebook post said.