About this lesson
Follow a swatter from a real fruit fly’s eyes down the giant fiber to its legs in 30 ms, then cut the wire. A free 10-minute lesson.
What happens, step by step
- 1
A swatter swoops at the fly. Tap Stimulate to fire the looming neurons (the swatter spotters).
They fire, and in a few thousandths of a second the giant fiber (the escape wire) fires too.
- 2
Tap Stimulate again. Follow the giant fiber (the escape wire) down into the nerve cord (like a spine).
The jump neurons (the leg kickers) fire within 30 milliseconds. They kick the middle legs, and the fly leaps away.
- 3
Now silence the giant fiber (the escape wire). We will send the swatter. Watch the jump neurons (the leg kickers).
The looming neurons (the swatter spotters) still fire, but the jump neurons stay dark. The fast escape is gone.
- 4
Tap the giant fiber (the escape wire) button again to switch it back on. We will send the same swatter.
The jump neurons (the leg kickers) fire again. Real flies also have slower ways out, but this is the fastest.
Questions this lesson answers
- Why are flies so hard to swat?
- A fly sees the swatter coming early, and a fast escape circuit launches it into the air in a few hundredths of a second, before the swatter lands.
- How fast is a fly’s reaction time?
- A fly’s fastest escape jump starts a few hundredths of a second after danger looms. A person needs about a quarter of a second just to react.
Key terms
Teacher guideStudent worksheet
