How do bats avoid flying into thin wires and other obstacles?

Most bats in the suborder Microchiroptera avoid obstacles, including thin wires, by using echolocation, a biological sonar system.12

By emitting short, high-frequency pulses of sound and listening for the returning echoes, bats can determine the distance, direction, and nature of objects in their environment. This system is highly sophisticated; research has shown that some bats can detect and avoid wires as thin as 0.08 to 0.1 mm in diameter.1

To navigate effectively, bats systematically alter their pulse output in three phases:1
* Search phase: Used for general orientation while cruising.1
* Approach phase: Initiated when an object is detected, involving an increased pulse rate and shortened pulse duration.1
* Terminal phase: Characterized by extremely rapid, short pulses as the bat performs final avoidance or interception maneuvers.1

While most bats rely on this acoustic system, some species also use vision for long-distance navigation and to detect motion or obstacles. Additionally, certain Rousette bats have independently evolved their own specialized echolocation system specifically for obstacle avoidance.31