Sarah Weiskopf, a wildlife biologist who led a new study which proved that leeches can be better at scouting some cryptic forest dwellers, has recruited 200 leeches to help her out in her new research work on animal survey.

Reports say Weiskopf teamed up with a scientist who had used camera traps in South Asia to study animals in the forests of Bangladesh, to recruit the leeches collected at 16 sites over a period of four days.

Collecting 200 leeches is much easier than it sounds. “When you walk around in the forest, you see them crawling on the ground,” Weiskopf says.

“And they come toward you because they want to find a meal. We just pick them up from branches, the ground or wherever you see them.”

Her team then plopped each little bloodsucker in its own test tube and carried them all home to her lab.

Weiskopf found traces of blood from 12 mammal species inside the leeches’ guts. If she had used 16 camera-traps instead, she would have needed about 6 nights of data to reach the same animal count. So leeches, she says, seem to be a faster way to survey for animals.