I'm currently reading a book entitled "A world without bees" which gives a complete overview of the historical disappearances of bee colonies and the suspected reasons. One of the parasites discussed is the Varroa mite which sucks the blood of the bee. This raised a question that I'd never even considered, and that is the size of the veins and arteries inside a bee, and the blood cells therein, and how tiny they must be. So, how different is bee blood to human blood? Do they have the same kind of blood but with smaller "bits"? And what about the heart - how different is that to a human heart? Does it have 2 chambers, too? Does it "lub-dup"? And then of course there are all the other organs! I guess that I'm so used to considering these on a human scale, that it's almost inconceivable that it's possible to fit all that in to something as small as a bee!