Fig 5. Formation of puddles in cargo holds.

Barges are typically mopped whenever the boat is docked at either its origin or destination point. Water from rain and cleaning activities drips from upper most floors (A) through rust holes in the cargo hold roof (B). Water accumulates in the bottom of the cargo holds (C), and Ae. aegypti eggs are laid on the edges of the puddles, hatching when the puddles are refilled with water.