I may have just found my favourite article on wikipedia:
"A puddle is generally small enough for an adult to step over, shallow enough to walk through, and too small to traverse in a boat or raft. Puddles can be a source of fascination for children, as well as attracting other small wildlife."
"In military terminology, puddles are "liquid terrain obstacles deprived of tactical importance""
Who knew? It's so deadpan, I love it.