A ‘pest’ can be defined as an animal that is detrimental to humans or human concerns. In the vegetable garden, the most common ones are slugs and snails, aphids (blackfly and greenfly being the most prolific) and the caterpillars of large, white and small, white butterflies (often collectively called cabbage white butterflies). In the spring, in some areas, wood pigeons can also be a nuisance — eating young brassica plants in particular. Fruits can also be devoured by a number of different birds and some rodents.