When insects encounter an artificial light in an otherwise dark environment, they often fly in confused circular paths around the light. One theory of why insects do so is that they believe a bright light surrounded by darkness represents an escape route. However, scientists investigating this phenomenon have found that, when a light is made to shine only upward, insects often fly upside down above the light and that, when a light is placed above the flight paths of insects, they fly below the light in a normal manner.
Which of the following hypotheses is best supported by the given information?This is a Conclusion question, and the correct answer will be a conclusion logically supported by the statements in the passage.
(A) Insects sometimes fly upside down in order to escape from dark spaces in which they find themselves.The passage mentions a theory regarding why insects "fly in confused circular paths" around "an artificial light in an otherwise dark environment," which is that they believe that a bright light surrounded by darkness represents an escape route.
At the same time, the fact that, in a different type of situation, insects fly upside down above a light does not support any theory about escaping. After all, if an insect believed a light to represent an escape route, the insect would not then fly above the light upside down. Rather, the insect would fly toward the light to escape.
Eliminate.
(B) Insects are confused by artificial lights only when they shine in more than one direction.This choice contradicts the information presented by the passage since insects appear to be confused by a light that shines only upward since they fly upside down above it.
Eliminate.
(C) Insects normally utilize the relative brightness of the sky to determine which direction is up.The passage says that insects do the following:
- are totally confused by a light surrounded by darkness
- fly upside down above a light that shines only up
- fly normally below a light that shines only down
These actions most clearly indicate that insects are somehow disoriented by lights other than ones that shine from above only.
Also, the fact that insects fly upside down above a light that shines only up indicates that they normally orient themselves by keeping their upper sides to a light.
All of this provides support for the conclusion that insects normally orient themselves by utilizing the relative brightness of the sky to determine which direction is up.
Keep.
(D) Insects trapped in a dark space with an opening to a lighted area will not leave the dark space.The passage says nothing that indicates that insects will not leave a dark space.
The do fly in confused circular paths around a light surrounded by darkness, but that situation is different from a dark space with an opening. In that situation the insects could be confused because, normally, they would escape by flying toward the light, but in that situation the light does not truly represent an escape route.
Also, the passage indicates that people observing insects flying in that way around a light have theorized that insects are confused because they believe that the light represents an escape route. If this theory is correct and insects can perceive escape routes, then they would be likely to use them to leave a dark space rather than remain in the space.
Eliminate.
(E) Insects whose usual flight paths are relatively low are not affected by artificial lights.The height of insects' flight paths is not mentioned, only whether a light was below or above their paths.
So, there's no reason to believe that insects would not be affected by artificial lights simply because their usual flight paths are relatively low.
Eliminate.
Correct answer: C