Youngsters used their scientific skills to test if sandless sandbags worked just how they should.

The children from the Duizendpoot School in Bunsbeek, Belgium, saw FloodSax sandless sandbags being demonstrated on Facebook by Adel Oueslati, owner of Belgium company Aquasorb.

They wanted to check if the claims were true that the FloodSax would expand from 200 grammes when dry to 20 kilos after being immersed in water in just three minutes.

They split up into four teams to test four of the FloodSax … and every one passed the test.

The youngsters also had a great surprise as Adel went to the school to see how they got on.

“They knew me as the man from the video so they were amazed to see me in the classroom,” he said. “They all have such inquiring minds and wanted to test their scientific skills in a real-life situation.”

The children then took the FloodSax outside to see how they could be stacked to stop floodwater before finally cutting them up to see the special gelling polymer inside to find out how that worked by absorbing the water.