在英國，有些人會把萬聖節南瓜丟棄在林地，想為野生動物提供食物，但其實反而危害了生態。這些南瓜會吸引老鼠、傳播疾病，並對土壤、植物及真菌造成有害影響。有些野生動物如像刺猬，吃了南瓜後會造成不適及腹瀉； 一些南瓜含有蠟燭或其他裝飾品，若被食用可能會害死野生動物。

In UK, the recent trend for discarding Halloween pumpkins in woodlands to provide food for animals is endangering wildlife. these pumpkins attract rats, spread diseases as well as bring harmful effect on soils, plants and fungi. wildlife like hedgehogs will get stomach upsets and diarrhea after feeding on pumpkins; some pumpkins contains candles and other decorations, and could kill wildlife when eaten. 

https://news.sky.com/story/dont-leave-halloween-pumpkins-in-woodlands-people-warned-12734903