The fledglings are growing and their parents have to tend to their every need. To do so they have to feed them, keep them away from predators but also keep the nest clean of droppings to avoid poor hygiene and parasites. What do the parent tits do with the faeces left by their little ones? Well, the fledglings do not just simply leave droppings in the nest, they instinctively face away from their parents, showing them their rear so that they can collect a small sac containing their offspring’s droppings. This ‘faecal sac’ is then removed from the nest to keep it clean. It is deposited some distance from the nest to avoid putting predators on their trail.