Cicadas are not inherently afraid of light, but their behavior can be influenced by it. While they are primarily nocturnal or crepuscular, meaning they are most active at dawn and dusk, bright artificial lights can sometimes disorient them or attract them, especially during mating season.
Understanding Cicada Light Behavior
Cicadas, those fascinating and often noisy insects, have a complex relationship with light. While they don’t "hate" light in the way a creature might fear a predator, their activity patterns and responses are certainly influenced by it. Understanding their natural behaviors helps explain why they might seem attracted to or repelled by certain light sources.
Are Cicadas Attracted to Light?
It’s a common observation that cicadas can sometimes be found congregating around outdoor lights. This attraction isn’t necessarily a deep-seated love for illumination. Instead, it’s often a byproduct of their natural instincts and the way artificial light can disrupt their typical activity cycles.
During their peak seasons, particularly when emerging in large numbers, cicadas are driven by the urgent need to mate and reproduce. Their natural activity is often concentrated during the warmer parts of the day and into the evening. Bright, artificial lights can mimic daylight, potentially confusing their internal clocks and drawing them towards the light source. This is especially true for newly emerged adults still getting their bearings.
Why Do Cicadas Seem to Avoid Light Sometimes?
Conversely, there are times when cicadas might appear to shy away from light. This is often linked to their natural predation avoidance. Cicadas are prey for many animals, including birds, bats, and even some mammals. While they are most active during twilight hours, they also have periods of rest.
During daylight hours, especially under the harsh midday sun, cicadas might seek shade or remain still to avoid detection by diurnal predators. If a bright light is suddenly introduced into a darker area where they are resting, they might react by moving away from the sudden, intense illumination. This is more of a startle response or a move to re-establish a comfortable, less exposed state.
Cicada Life Cycle and Light Exposure
The cicada’s life cycle is a significant factor in how they interact with light. Most of their lives are spent underground as nymphs. This subterranean existence means they have very little direct exposure to light for years.
Nymph Stage: The Underground Life
For 13 or 17 years, depending on the species, cicada nymphs live beneath the soil. They feed on tree sap and grow through several molts. During this extensive period, light is not a factor in their development or behavior. Their world is dark, damp, and focused on growth.
Emergence and Adult Life: A Sudden Shift
The emergence of adult cicadas is a dramatic event. Triggered by soil temperature, they tunnel to the surface and molt one last time into their winged adult form. This transition from complete darkness to the bright, open world is a significant change.
The newly emerged adults are often soft and vulnerable. They may seek out higher ground, like trees, to complete their hardening process and to begin their search for mates. This period of vulnerability can make them more sensitive to their surroundings, including light.
Do Cicadas Hate Artificial Lights?
The question of whether cicadas "hate" artificial lights is best answered by understanding their behavioral responses. They don’t possess an emotional aversion, but their actions suggest a complex relationship.
Nocturnal and Crepuscular Tendencies
Many cicada species are primarily nocturnal or crepuscular. This means they are most active during the night or at dawn and dusk. Their songs, which are so characteristic of summer, are often loudest during these times.
Artificial lights can disrupt these natural rhythms. A bright porch light or streetlamp can create an artificial dawn, potentially drawing cicadas in. This can lead to them becoming active when they might otherwise be resting or less visible.
Mating Calls and Light Attraction
The male cicada’s song is a crucial part of their mating ritual. They sing to attract females. Sometimes, the combination of warm evening air and bright lights can create an environment where cicadas are more vocal and more easily drawn to the light source.
This can lead to clusters of cicadas gathering around lights, creating a visual spectacle. It’s not that they are seeking the light itself, but rather the conditions it creates or the way it influences their natural urge to sing and find mates.
Practical Tips for Managing Cicadas and Light
For homeowners and gardeners, understanding cicada behavior around lights can help manage their presence. While cicadas are generally harmless, their sheer numbers can be overwhelming for some.
Reducing Attraction to Lights
- Minimize unnecessary outdoor lighting: If possible, turn off lights when not in use.
- Use motion-sensor lights: These only illuminate when needed, reducing constant attraction.
- Consider yellow or sodium vapor bulbs: Some anecdotal evidence suggests these lights are less attractive to insects than standard white or blue-spectrum lights. However, research on cicadas specifically is limited.
- Shield lights: Directing light downwards can prevent it from spreading widely and attracting insects from a distance.
Cicadas and Your Garden
While cicadas are a natural part of the ecosystem, their nymphs can sometimes damage young trees by feeding on roots. Adult females lay eggs in tree twigs, which can cause flagging (wilting) of small branches.
- Protect young trees: During peak emergence years, consider covering very young or vulnerable trees with fine netting.
- Prune damaged twigs: After egg-laying, prune any flagged twigs to help the tree recover.
People Also Ask
### Do cicadas bite humans?
Cicadas do not bite humans. They lack the mouthparts necessary for biting. Their primary defense is their loud noise and their ability to fly away. You might accidentally touch one, and it could crawl on you, but it poses no threat of biting.
### Are cicadas dangerous to pets?
Cicadas are generally not dangerous to pets. While some pets, like dogs and cats, might try to catch and eat them, cicadas are not toxic. However, eating too many cicadas could potentially lead to an upset stomach or a blockage if a large number are consumed.
### When do cicadas emerge in my area?
Cicada emergence is tied to specific broods and their 13 or 17-year cycles, as well as local soil temperatures. The most common periodic cicadas emerge in late spring and early summer. You can often find emergence maps online specific to your region and the current year to determine if a major emergence is expected.
### How long do adult cicadas live?
Adult cicadas have a relatively short lifespan, typically living for only about four to six weeks. Their primary purpose during this time is to reproduce. Once they have mated and the females have laid their eggs, their life cycle is complete.
Conclusion: A Complex Relationship with Light
In summary, cicadas don’t "hate" light, but their behavior is definitely influenced by it. Their natural nocturnal or crepuscular activity, combined with the potential
