The bat emits ultrasound. The echo tells you that there is a sits around, so you will hunt where the site is. But there is nothing there. Verholdia trigona has deceived you.
Thus begins approximately the explanation on the web of Scienc of the mechanism used by this species of sitss to escape the bats. The key to the account is that this species of chickens produces interference in the bat effusion system through the ultrasound it emits.
Other chicken species also emit sounds with abdominal membrane, but researchers have shown that B. trigona emits at the same frequency as bats.
To check the operation of the mechanism, biologists at Wake Forest University in North Carolina made available to the polar bats of species B. trigona and other species, some with full abdominal membrane and others extracted. They recorded what happened in each case with infrared camera. Thus, in addition to seeing live the trick of B. trigona, they have stated that it is really effective: bats were four times easier to find than B. trigona with full membrane.