A lot of schoolyards in Africa are built near wild habitats, which sounds like a cool idea to travelers but not the locals.

Animals, especially elephants, often pass near schools and roads, bringing danger to students.

That's particularly the case in Taita Taveta, Kenya, where at least 20 people were killed by elephants between 2014 and 2016.

To prevent more of these kind of tragedies, four girls in a local secondary school spent months creating a gadget to help prevent deaths by elephants.

The wallet-sized gadget can sense nearby elephants, then lets out a siren and light in order to scare them away.

The device can also send an SMS to local rangers for help.

How useful is this device? Watch the top video to find out.