The person wanted to use her ear to detect the buffalo herd, where did she put it?\nOptions:\n- on the buffalo\n- person's head\n- side of head\n- ground\n- serial killer's bedroom
Let's think step by step.
ground
When buffalo herd arriving from far you can hear noise putting ears on ground.

Runnning buffalo herd makes large impact on ground.

.

The final answer: ground