In this video from Zoos Victoria, we get to meet Healesville Sanctuary’s twin 4-month-old male platypuses. So cute, these odd little guys.

Their handlers have had their eyes on the tykes from birth, thanks to a camera embedded in their underground burrow. Platypus newborns don’t leave the burrow for four months, so the zookeepers didn’t know what they’d see: “It was a bit like peeking into the nursery window for the first time,” says the sanctuary’s researcher Jess Thomas.

When they were born, the twins were about the size of jelly beans. Two little, duck-billed jelly beans. Now, at four months, they’re about half of their eventual, adult size. They’re also off their mother’s milk, and are, essentially, fully independent.

The twins aren’t identical—one is a little bigger than the other. They also have different personalities. One, “Wriggles,” is a go-getter, generally brave, and the first sibling in the water and swimming. His brother is a bit more timid— they call him “Shy”—hesitating a few days before taking his first dip. Shy also likes to hide, burrowing under his handler’s chin, although in the video she doesn’t seem too sure about this. The handler’s reaction got me wondering if platypuses bite: They don’t. They don’t have teeth, but they do have spurs on their legs with a venom that can cause a really nasty sting.