2:00 minutes (1.62 MB)
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Sapsuckers, a specialized group of woodpeckers, don’t actually suck sap. After pecking neat rows of small holes in trees to cause the sugary liquid to flow, the birds lick it up with tongues tipped with stiff hairs. So why doesn’t a sapsucker’s beak get stuck shut? Part of the answer may lie in the sapsucker’s saliva. Scientists conjecture that the bird’s saliva contains a substance that prevents sap from congealing, a sort of anticoagulant. When a sapsucker pecks holes in a tree’s bark, sap flows freely. But when researchers do the same, they can’t get the sap to flow nearly as well!