After scooping up a spider into a tissue and flinging it outside a few days ago, I began to wonder if insects can have concussions too. Yes, I know that spiders aren’t insects, but this question lead to further research of concussions in other animals. It was about a metre drop for the spider, which is about 100 times its body length. Imagine falling a distance of 100 times your body length. That can’t possibly be healthy.
It turns out, concussed fruit flies have been investigated before. Fruit flies have brains similar to humans, with a hard casing around it and cerebrospinal fluid cushioning. The fruit flies experienced brain damage and had symptoms just like humans, such as loss of consciousness, loss of coordination, and an increased risk of death. The negative effects depended on the severity of the impact, age, and genes.
On the other hand, woodpeckers don’t get concussions. Woodpeckers peck at about 24 km per hour to search for insects, build a nest, and emit a mating call. However, the woodpecker’s brain is packed tightly in its skull, with little cerebrospinal fluid to slosh around in. This reduces the effect of shock waves, which protects the brain from damage.
Now, what about snakes? A snake strike lasts only 44 to 70 milliseconds. A human would lose consciousness if they tried to move that fast. Since the snakes move so quickly, they can experience up to 30 times the force of gravity. Fighter pilots doing extreme maneuvers in short periods of time can lose consciousness at 10 times the force of gravity as blood cannot come back to the brain quickly enough to oxygenate it. How can snakes do it? Snakes have very mobile skulls with many joints, which allows them to absorb the shock and displace the impact of the strike. This allows snakes to prevent getting concussions even as they strike at incredibly high accelerations.
So there you go. Something to think about next time you flick a bug away.
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