U.S. Federal Law UL 325 has required garage door sensors since 1993. If something breaks the laser connection between the two sensors, the garage door will stop closing or even reverse. This legal requirement has been greatly beneficial for improved safety.
However, some kids try to make a game of beating the garage door as it closes by leaping over the door sensors. It's important to tell your children why this is dangerous such as, they could accidentally trip and fall, or they could accidentally get caught underneath the door if the sensors are faulty. While modern garage doors have auto-reverse features, you shouldn't tempt these safety features should something go wrong.
Even if your kids aren't playing around with the sensors, they may leave toys or a bike near an open garage. It's important to remind them to put their belongings all the way inside the garage when they are done.
Besides going over safety rules with the kids, regularly inspect these sensors when you leave the house. Sometimes the door sensors can become misaligned, and so the auto-reverse feature of the garage may be faulty. Every door is different, but your sensor LEDs may flash or turn off completely if something isn't right. If something seems amiss, contact a garage repair service.