Turn on a light outside at night, and it won’t be long before lots of insects start gathering around it. This behavior has led to a popular comparison for attraction, “like a moth to a flame.” However, according to a new study published in the journal Nature Communications, it turns out that insects aren’t “attracted” to artificial lights, but rather confused by it.
The new finding is based on a theory about insect orientation (定位). Due to their small and lightweight bodies, insects experience less air resistance, allowing them to achieve higher accelerations (加速度), which in turn makes it challenging for them to sense up and down during flight. So, they typically rely on stable light sources like the moon and stars to orient themselves at night, keeping the sky at their backs to stay upright. However, the introduction of artificial lights confuses their natural sense of direction. The insects you see circling street lights, in other words, are probably lost.
To reach these conclusions, scientists used high-resolution cameras to film insects flying around artificial lights in Costa Rica. They also attached tiny sensors to insects and filmed motion-capture videos of them in flight. In this way, researchers can slow down the insects pace and study their movements in greater detail. The videos showed insects turning their backs toward sources of artificial light — even at the price of flipping over or crashing.
This can be dangerous for insects, as circling around artificial lights can put them at risk from enemies, exhaustion, and starvation, causing many to die before morning. Night artificial light is a major cause of insect population loss, which could severely impact crop pollination and food supplies for larger animals, including humans. “Insects have been flying around for 370 million years, and it’s just in the last 150 years that it’s really gone wrong for them,” says entomologist Samuel Fabian of Imperial College London. “If we don’t want to influence large amounts of insect populations, we should not have lights shining up into the sky.”
【小题1】What have scientists found out about insects?| A．Artificial lights can disturb their sense of direction. |
| B．Their populations are in decline. |
| C．They often fly quickly during the night. |
| D．Their eyesight is well adapted to light changes. |
| A．By detecting the living environment of insects. |
| B．By monitoring the insects’ brain activity during flight. |
| C．By making videos to study insects’ movements. |
| D．By building models to analyze insects’ motion patterns. |
| A．To stress the importance of insects to food supplies. |
| B．To appeal to people to reduce light pollution. |
| C．To show the reasons for insects flying around lights. |
| D．To explain the effects of insects’ death on human life. |
| A．How Artificial Lights Impact the Ecosystem |
| B．What Leads to the Loss of Insect Populations |
| C．How Insects Orient Themselves in the Flight |
| D．Why Insects are Attracted to Lights at Night |
