PrepTest 128, Section 2, Question 4
In the spring and fall, eastern pipistrelle bats(70 more words not shown)
Which one of the following,(9 more words not shown)
- AThe researchers studied(17 more words not shown)
- BEastern pipistrelle bats(19 more words not shown)
- CEastern pipistrelle bats(19 more words not shown)
- DBecause of the(24 more words not shown)
- EDuring the periods(22 more words not shown)
Reading the argument
More insects are available on warm nights, so I can see why bats would want to leave the cave then. Their food is outside, and warm nights offer more of it.
But how do the bats know it's warm outside?
They're roosting deep inside a cave whose temperature hardly changes from one night to the next. The researchers nevertheless observe more bats leaving on warm nights. A reason to prefer warm nights doesn't yet explain how the bats detect them from inside.
What we’re looking for
Maybe there is another cue: changes in pressure, moisture, or something else the bats can sense. Those are possible explanations to look for, not facts we've been given. The question asks us to explain the finding, so I want a way for conditions inside the cave to signal conditions outside it. We only need to explain the spring and fall behavior described; the opening sentence doesn't tell us what happens in the other seasons.
Working the answers
- A
A difference between female and male hunting success doesn't explain how the studied bats know when to leave. Even if females catch more insects on warm nights, we still need a cue that lets them distinguish those nights while they are in the cave.
- BCorrect
The bats can detect pressure changes inside the cave, and those changes closely track changes in outdoor temperature. Now they have information about the outside even though the cave's temperature remains steady. That supplies the missing mechanism linking warmer nights with more departures to hunt.
- C
This supplies another reason that being outside on cold nights could be undesirable. It doesn't tell us how the bats detect a cold night before leaving. We already understood why warmer nights would be attractive because more insects are available; the puzzle concerns how the bats respond to a temperature change they cannot feel inside the cave.
- D
Eating more in spring and fall than in summer concerns a difference between seasons. The finding concerns differences between warm and cool nights within spring and fall. A seasonal change in appetite doesn't explain how the bats detect the conditions on a particular night.
- E
Knowing that more than half the bats left on most evenings doesn't explain why more left on warm evenings than on cool ones. That overall departure rate could hold with or without the observed response to outdoor temperature. We still need a way to account for that response.
More Paradox questions
Learn the LSAT our way
Our platform drills Paradox questions at your level and adjusts as you improve.