Lily's diamond had been stolen from her house. When detectives Ethan and Ethel arrive at the house, they squeezed through the corridor that could only fit one person at a time and asked Lily who did she suspect. Lily told the two that she heard engines, gave a list of three suspects and hurled them out of her house to get investigating. The three suspects are as follows: Ben, who only has 3 huge caravans; Million, the owner of 10 dogs; and Hank, a proud motorbike collector who has over 50 motorbikes in his garage. Who is the thief? -Riddles