Final answer:
Bumblebee bats primarily use echolocation to navigate and locate prey by emitting sound and sensing reflected sound waves. They also rely on camouflage to evade predators. Some bat species exhibit group defense which can be viewed as a form of cooperation among individuals.
Step-by-step explanation:
Bumblebee bats, like other bat species, have a variety of defense mechanisms. One prominent method they use for navigating and finding food in their environment is echolocation. They emit sound and sense the reflected sound waves to form a 'picture' of their surroundings. This process allows them not only to avoid obstacles but also to locate prey. This ability is critical, especially since bumblebee bats operate in the dark.