One of the great things about Science is, no matter how much time you spend working on something, there is always some super cool fact that takes you by surprise.
In this instance I discovered something about flies that I was completely unaware of until I went to a Fly seminar. Flies have 3 hearts - the main heart and an additional small heart for each wing. That's ONE more than a time-lord!
I was hoping I could find a video of them beating but have failed. I'll try and ask the person who gave the talk if I can borrow the clip.
I guess this is true of many winged insects. Which makes me wonder if a dragonfly has 5 hearts?