Flies around the house have
always been pesky, as they swarm around and cause our food to spoil, and I’ve
always thought that the only ways to get rid of flies are to sway something at
them, swat them flat or put some icky, sticky fly paper around. But having
encountered this interesting picture made me think that my ideas about it are
very limited, and I immediately wondered about the rationale behind the capability
of water-filled plastic bags in driving flies out.
This picture was shared by my
dear friend who’s currently in Korea, and he said that this is a typical way
for restaurants there to get rid of flies. He was told that the shape of the
human hand apparently scares insects. Other people claimed that the theory
behind it is not necessarily with the hand-shaped bag – it’s with the light
that is reflected by the water inside the bags, and it may either distort or
blur insects’ vision, causing confusion. Some sites mention that pennies should
be placed inside the water-filled bag: as the water magnifies them, it would
resemble a bigger insect’s eyes, thereby scaring flies away.
I eventually read further
along, just to get some reliable scientific explanations to back this up.
According to the Tennessee Farm Bureau Federation, it’s really not about the
pennies – it’s about the light that is refracted as it goes through the bag. If
you go back to your biology notes from high school, you would find out that the
fly’s eyes are largely complex, made up of about a thousand “mini eyes” that
don’t focus or move. The refracted light causes distorted images as they are
perceived by these non-focusing eyes, and these stimuli are interpreted
differently by the fly’s brain. As a result it causes visual and spatial misinterpretation
and the natural response of flies are to fly away from the refracted light.
However, there seems to be
very limited information that really supports water-filled plastic bags as a
way to get rid of flies. Yet while we’re waiting for some revelation coming
from expert minds, wouldn’t the fun out of it be reason enough to give it a
try?
Links:
http://www.tnfarmbureau.org/content/pennies-bags-water-make-flies-flee
