How many species of beaver are currently alive?
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Beavers are hands down the most extra animals on the planet. These paddle-tailed engineers have been reshaping North American waterways like they've been playing SimCity for millions of years. They've got orange teeth that grow nonstop, can stay underwater for 15 minutes without coming up for air, and when they're pissed off they slap the water so everyone knows. How many species of beaver currently exist?
