"All the robots are told is where products are located and where they need to go. From there, the robots, which look like massive orange Roombas, figure out the rest. They locate the stack of shelves with the needed product on it, slide beneath the stack to pick it up and then find their own routes from the stacks of stuff to human operators. And they manage to find just the right time to get themselves recharged for five minutes out of every hour." - Steven Perez from Bookmarklet