A) You are correct. Canada geese are now classified as pests and a family of them certainly does produce a lot of droppings and mess. As for the danger to your grandchildren, there is some possibility of salmonella poisoning or some other unpleasant disease through the droppings. However, my children had geese and a wide range of other creatures as pets and they survived. A little dirt is probably good for the immune system. I would be far more worried about the possibility of them contracting Weils disease from rats which may be present. If you enjoy a goose on the table, why not substitute some domestic goose eggs in the Canada?s nest next year and let them rear your Christmas dinner for you!