Someone here really needs help!!

Of all the weird hitty bangy things in our house, that is one I've never come across, and I'm intrigued. It sounds a lot like something I played at school once. A thing like a fizzy pop bottle, but made from a bamboo trunk, it had notches cut along the side and was played with a stick, knife, pen, knitting needle, anything that wasn't going to break, but made a nice sound a bit like a grasshopper....

LTS