A group of students in the Philippines has found a way to convert poo from stray dogs into a mixture for bricks. They aim to rid the streets of excrement and say they could also lower construction costs. Eighth graders in the Payatas district north of the capital Manila air-dried dog feces, which were then mixed with cement powder and molded into rectangular bricks. The students say their "bio bricks" are ideal for sidewalk pavements or small structures like backyard walls.