It is made from left over pieces of tech and is based on tracking equipment used in warehouses.
Making up the tracker is a specially designed computer chip and aerial - which has been created to be thinner and lighter than those used to track bigger insects.
Around 50 have been made so far and the idea is to use them to track the bees as they move around in the wild.
Experts are hoping that this new technology will allow scientists to have a better understanding on why the number of bees are declining.
A tiny new tracker designed to monitor bee behaviour is being tested by experts in London.