New research into feral cats reveals the predators can be a fat and healthy lot, gorging on everything from fairy penguins to McDonald’s. The study of stomach contents in Tasmania has found the pests can consume massive amounts. Cats store fat on internal organs and breed out of season. Zoology honours student, Kylie Cahill, has dissected 85 feral cats as part of her study. All but a couple of the females had recently bred and were lactating, despite summer being the normal kitten season. She found many are twice the size of their domestic cousins, weighing up to 8kg.They also have longer fangs and bigger muscles in their shoulders, neck and forelimbs.