They are part of the 'Water Rats Shipping Company', which consists of one ship with a Captain and 1st Mate. On their travels on the waterways, they spotted Towser’s Summer House and thought it would be the ideal place to situate their new head office. The Captain offered to buy the Summer House for 2p, but refused. Eventually they agreed on a price of 4p, with the condition that Towser got a free ride aboard their ship. They weren't happy when Towser loaded all his furniture on board and thought the trip would take all summer. They panicked and tried to sell him back the summer house, but the crafty Towser would only buy it back for 2p, so making a 2p profit. Of course, the Water Rats weren't pleased, but they accepted his offer, unloaded his items and sailed away.