I remember a funny story when I was a kid living in Santo Domingo in the 70's.
Many a weekend we used to visit the isolated beaches of the Eastern DR (before they where developed) using an inflatable Avon boat to reach remote places. Back at the house we had an Alsation dog. Each day he would be fed a large bowel of food. For some reason he appeared to be getting thinner and thinner. So we dewormed him, took him to the vet, checked him out and they could find nothing wrong with him. One day I noticed after his food had been served which was around the back of the house that he seemed scared to approach his plate. It was then that i realised the reason why. From under his house around six large landcrabs appeared and consumed the contents of his plate and he was too scared to go near them. What had happened was they had been brought back to the house from the beach in a small form rapped in the inflatable boat and had grown into fullsize!