Leeches might be a tool to help track down rare or endangered animals in the wild, say researchers.
The blood-sucking worms store DNA of their prey in their systems which can be extracted to test for the presence of other animals.
According to the New Scientist, Tom Gilbert of the University of Copenhagen in Denmark, fed goat blood to leeches in order to assess how long the goat DNA would remain in their system.
The leeches stored the goat blood for an astonishing four months.
The scientist then collected the blood from 25 leeches in a remote part of Vietnam finding DNA from numerous rare animals including striped rabbits, a muntjac and rare breeds of goats and badgers.
Many of the animals have yet to be seen in the area and the leeches serve as the only confirmation the animals had been there.
“It is a very easy way to get a snapshot of what animals are in the area,” said Gilbert, according to Nature.
According to Phys Org, tracking rare or endangered animals is expensive and difficult, with many species living in remote jungles.
Gilbert's method offers an easier and cheaper alternative as leeches do not need to be sought.
"They look for you," says Gilbert, according to the New Scientist.