As someone who cares for about 100 raccoons a year, Melanie Piazza knows that a listless, placid raccoon is not a healthy one. "A lot of the calls were, 'There's a raccoon sitting on my porch and he hasn't moved all day, and I open the door and he doesn't move,' and that's not normal," said Piazza, the director of animal care at WildCare, a wildlife refuge in San Rafael and one of several Bay Area care centers baffled in recent years by a rise in strange raccoon behavior. The centers would occasionally collect raccoons like this and try to...