[单项选择]Vibrations in the ground are a poorly understood but probably widespread means of communication between animals.
It seems unlikely that these animals could have detected seismic "pre-shocks" that were missed by the sensitive vibration-detecting equipment that clutters the world’s earthquake laboratories. But it is possible. And the fact that many animal species behave strangely before other natural events such as storms, and that they have the ability to detect others of their species at distances which the familiar human senses could not manage, is well established. Such observations have led some to suggest that these animals have a kind of extra-sensory perception. What is more likely, though, is that they have an extra sense-a form of perception that people lack. The best guess is that they can feel and understand vibrations that are transmitted through the ground.
Almost all the research done into animal signaling has been on sight, hearing and smell, because these are s
A. slugging them out for territorial defense for their of springs.
B. fighting with each other to own harems of females.
C. their act of aggression against other animals.
D. competing fiercely with each other for locating meals.