Flies are a common nuisance. Their behavior, including attraction to or avoidance of certain areas, is influenced by color. Understanding how flies perceive colors offers insights into managing their presence. This article explores the colors flies avoid, the science of their vision, practical applications, and colors that attract them.
Colors Flies Avoid
Flies show an aversion to specific colors, making certain environments less appealing. Research suggests yellow repels flies. This is partly because flies struggle to differentiate yellow from white, a color associated with open sky and lacking cues for food or shelter.
Beyond yellow, green and certain shades of blue are also less attractive to flies. These colors might not register as vividly in the ultraviolet (UV) spectrum that flies perceive, less noticeable or stimulating. While no color provides a complete barrier, using these less appealing hues contributes to deterring flies from specific areas.
The Science of Fly Vision
Flies possess compound eyes, different from human eyes. These complex visual organs consist of thousands of individual light-sensing units called ommatidia, each a tiny, independent photoreceptor. This mosaic-like structure provides flies with a wide field of view, 360 degrees, for efficient movement detection.
Flies have a limited range of color perception compared to humans. While humans have three types of color receptor cells, flies possess two or, in some species, four. Flies are particularly sensitive to ultraviolet light, a part of the spectrum invisible to human eyes, and use this sensitivity to navigate their environment and locate resources. They cannot see the color red, which appears as black to them. The perceived brightness and saturation of different colors influence their behavior, guiding them toward or away from specific visual cues.
Practical Applications of Color Deterrence
Understanding flies’ color preferences provides practical ways to deter them. Painting outdoor structures like sheds or porches in colors such as yellow or light green makes them less inviting. Choosing outdoor furniture in these hues also reduces fly congregation. Similarly, wearing lighter-colored clothing, particularly yellow or white, when outdoors helps avoid flies, as dark colors tend to attract them.
Some fly traps utilize color to either attract or repel flies, depending on their design. While color alone is not a definitive solution for fly control, incorporating color deterrence as part of a broader strategy is beneficial. Combining color choices with other methods, such as maintaining cleanliness and eliminating breeding sites, contributes to more effective fly management.
Colors That Attract Flies
Understanding what colors attract flies provides a complete picture of their visual preferences. Flies are drawn to blue tones. Blue is frequently used in fly trap designs. Some research suggests flies may mistake blue objects for food sources or animals, due to how their visual system processes blue and green light.
Darker colors, including black, brown, and dark blue, also tend to attract flies in outdoor environments. These colors absorb heat and create shadows, mimicking visual cues flies use to find shelter or food. Highly reflective surfaces also draw flies, as light reflection and refraction may confuse them. This attraction to reflective surfaces is due to their sensitivity to light changes.