LSAT 128 | Section 2 | Logical Reasoning: Q4

LR Question 4 Explanation

QUESTION TEXT: In the spring and fall, eastern pipistrelle bats …

QUESTION TYPE: Paradox

PARADOX: More bats leave their caves on warm nights since that’s when their prey is abundant. But the temperature in their caves always stays the same.

ANALYSIS: The key question is how the bats know that it’s warm outside. We know they feed on flying insects, which are more abundant on warm nights than cool nights. But the stimulus also says the temperature inside their cave remains pretty much constant.

So how do the bats know the conditions outside before leaving? The correct answer should explain how they detect external temperature differences while inside the cave.

___________

1. If female bats catch more insects on warm nights than males, that may explain why female bats benefit more from leaving, but it doesn’t explain why more bats overall leave on warm nights. It doesn’t resolve how they detect the outside temperature in advance.
2. CORRECT. If bats can detect barometric pressure changes inside the cave that correlate with outside temperature, they have a way of knowing when it’s warm before leaving. This explains their behavior.
3. If bats struggle to stay active in cold, that explains why they prefer warm nights. But it still doesn’t explain how they know what the temperature is outside in the first place.
4. This explains differences between seasons, but it doesn’t explain how the bats know the temperature outside.
5. This is telling us that most bats (over half) left on most evenings. That doesn’t help us explain the paradox.