“White bread in particular has no real nutritional value, so while birds may find it tasty, the danger is that they will fill up on it instead of other foods that could be more beneficial to them,” says a spokeswoman for the Royal Society for the Protection of Birds.
Even more disturbing, feeding ducks bread can cause a wing deformity known as “angel wing” or airplane wing”.
According to the National Geographic, “Angel wing is a condition where the last joint on the wing is distorted and causes the end feathers to stick out laterally—sideways—instead of lying flat against the body. This prevents the bird from flying.”
Feeding ducks bread also makes them reliant on humans for food, and dissuades them from foraging and eating healthy food from their natural habitat like worms.
Uneaten bread not only attracts rats and other predators, it grows mould that can make ducks and other animals sick. It also contributes to the growth of harmful algae.
So what’s safe to feed ducks?
Try some seedless, halved grapes, as well sunflower seeds, cucumber, peas, beans, broccoli, beets, squash, flowers, alfalfa, tomatoes, eggplant, bananas (no peel), pineapple, pomegranate seeds, scrambled eggs, dry cat food or dog food, and rice.
This article originally appeared on Better Homes and Gardens.