According to Wikipedia, cats on board of sea service ships were a common feature on many trading, exploration, and naval ships, and dates back to ancient times. Cats have been carried on ships for many reasons, the most important being to catch mice and rats. These rodents aboard a ship could cause damage to ropes, woodwork, electrical wiring, the crew’s food and the products itself. Rats and mice were also sources of disease, which is dangerous for ships that are at sea for long periods of time. Over the years, the crewmen of those ships have developed a special affection towards the adorable cats who have joined them for those long trips.