Yesterday, two Brooklyn elementary school students were arrested for allegedly putting rat poison in their teacher's water. The two boys, ages 9 and 12, allegedly put "a substance consistent with rat poisoning" in 62-year-old Johanna Cherepany's water bottle at PS 315 in Flatbush on Monday morning. Officials say the students did it because, basically, some boys just want to watch the world burn: "The understanding is the 9-year-old wanted to see what the reaction would be. It's unfortunate where kids get these ideas," Police Commissioner Bratton said about one of the boys. "Fortunately we've got it handled. But God knows where kids get these ideas." A better question might be: when did the days of whoopee cushions and cell phone pranks give way to kids dabbling in sociopathy?

The teacher had told police she became nauseous after drinking the water; at least one other student later came forward and said they saw the two boys put something in the water. The teacher was treated for her illness and has recovered; the day after the incident, she went to the 70th Precinct station house to report the incident. Both students have been charged with reckless endangerment and assault.

"Thank God the teacher is OK and will make a full recovery,” Mayor de Blasio said of the incident. Cops add that they found more of the rat poison in the backpack of the 9-year-old, who turns 10 next week. This will probably be an even worse birthday for that kid than it was for us that time mom hired Puddles the depressed (but sonorous) clown.