Question 151·Easy·Central Ideas and Details
Researchers studying honeybees observed how the insects find their way back to the hive after foraging. On sunny days, the bees use the sun’s position in the sky as a compass. When thick clouds hide the sun, however, the bees switch to sensing Earth’s magnetic field to stay on course. In laboratory trials where both sunlight and magnetic cues were blocked, the bees became disoriented and could not navigate effectively.
According to the passage, what do honeybees primarily rely on for navigation when the sky is overcast?
For detail questions like this, first restate the question in your own words (here: “What do bees use to navigate when it’s cloudy?”), then scan the passage for the specific condition or keyword ("thick clouds," "hide the sun"). Read that sentence carefully, identify the exact phrase that answers the question, and choose the option that most directly restates that phrase. Avoid bringing in outside knowledge or picking answers that sound plausible but are not supported by the text.
Hints
Match the condition in the question to the passage
Find the sentence in the passage that describes what bees do when thick clouds hide the sun. That is the part that matches "when the sky is overcast."
Focus on the “switch”
Notice that the bees use one thing on sunny days, but the passage says they "switch" to something else when clouds block the sun. What exactly do they switch to?
Ignore outside knowledge
Do not rely on what you may have heard about how bees or other insects usually navigate. Base your answer only on what this passage explicitly says they use under cloudy conditions.
Step-by-step Explanation
Locate the part of the passage about cloudy skies
The question asks about honeybees’ navigation "when the sky is overcast." In the passage, this is described in the sentence: "When thick clouds hide the sun, however, the bees switch to sensing Earth’s magnetic field to stay on course." Overcast skies are the same idea as thick clouds hiding the sun.
Identify what changes under those conditions
On sunny days, the bees use "the sun’s position in the sky as a compass." But the question is not asking about sunny days. It is asking what they rely on instead when clouds hide the sun. The key phrase is that under cloudy conditions, the bees "switch to" another method of navigation.
Match the key phrase to the correct answer choice
The passage clearly says that, when thick clouds block the sun, the bees "switch to sensing Earth’s magnetic field to stay on course." The answer choice that directly matches this is Earth’s magnetic field.