In the episode where Timmy goes to his award ceremony,Timmy wishes he was invisable,so Wanda changed into a bat (animal) to see Timmy, if she wasn't a bat (animal) then she wouldn't have been able to see him, yet when she turned into a bat (object) she asked "I'm sorry Timmy, would you like a swing?" and she turned around and looked strait at him! How is that possible? He was still invisable!