PT  - JOURNAL ARTICLE
AU  - Matherne, Marguerite E.
AU  - Cockerill, Kasey
AU  - Zhou, Yiyang
AU  - Bellamkonda, Mihir
AU  - Hu, David L.
TI  - Mammals repel mosquitoes with their tails
AID  - 10.1242/jeb.178905
DP  - 2018 Oct 15
TA  - The Journal of Experimental Biology
PG  - jeb178905
VI  - 221
IP  - 20
4099  - http://jeb.biologists.org/content/221/20/jeb178905.short
4100  - http://jeb.biologists.org/content/221/20/jeb178905.full
SO  - J. Exp. Biol.2018 Oct 15; 221
AB  - The swinging of a mammal's tail has long been thought to deter biting insects, which, in cows, can drain up to 0.3 liters of blood per day. How effective is a mammal's tail at repelling insects? In this combined experimental and theoretical study, we filmed horses, zebras, elephants, giraffes and dogs swinging their tails. The tail swings at triple the frequency of a gravity-driven pendulum, and requires 27 times more power input. Tails can also be used like a whip to directly strike at insects. This whip-like effect requires substantial torques from the base of the tail on the order of 101–102 N m, comparable to the torque of a sedan, but still within the physical limits of the mammal. Based on our findings, we designed and built a mammal tail simulator to simulate the swinging of the tail. The simulator generates mild breezes of 1 m s–1, comparable to a mosquito's flight speed, and sufficient to deter up to 50% of mosquitoes from landing. This study may help us determine new mosquito-repelling strategies that do not depend on chemicals.