Passage Summary: Squirrels heat up their tails when trying to scare off rattlesnakes, and since snakes can 'see' heat, scientists think this is a specific defense tactic.

Conclusion: The squirrel's tail heating up likely serves as a mechanism to repel rattlesnakes.

Reasoning: Rattlesnakes possess infrared-sensing organs, and squirrels specifically heat their tails while engaging in defensive harassment behavior.

Analysis: To strengthen this hypothesis, we need to bridge the gap between the presence of heat and the actual effect on the snake. A strong answer might show that this heat-tail behavior is a targeted response used only against predators that can actually sense heat. If squirrels don't heat their tails for snakes that lack infrared organs, it suggests the heat is a deliberate, specialized weapon.