They're slippery little bubs, aren't they?
I once lost mine on a beach, though I was watching her like a hawk. She was 2, and I turned my head to answer a friend who'd told me to chill out. "I can't, she's a mini Houdini!" Looked back and she'd disappeared. I scoured the tiny beach but couldn't see her anywhere. I asked a man had he seen her - gave description - and he pointed up the cliff face and just said, "Her?" If I'd had time, I think I'd have decked him for being so flippant, but my ambitious child was actually climbing the cliff so I had to go and rescue her!
Afterwards, my friend said, "I see what you mean!" She had the fright of her life. My DD was just fine, though!