The farming conservation organization, Conservation Grade, has threatened that some of the UK's farmland animals could become extinct within 25 years. They include the harvest mouse, the small agile rodent found along field margins near cereal crops. Its numbers have fallen drastically over the last few decades as farming has intensified with the loss of hedgerows, drainage of reed-sedge habitats, and increased use of pesticides, so it has been added the UK Red List. This sweetie makes its distinctive ball-like nest in hedgerows, so its is particularly vulnerable to hedge cutting and removal. Helping this mouse can be quite easy, simply making sure hedgerows are not cut before the fruits and nuts have been removed in autumn helps the animal survive winter, together with leaving grassy margins around fields.
Some conservation groups have been placing tennis ball nests in appropriate sites to encourage the harvest mouse to return. The tennis ball is the perfect size of the mouse and it's highly visible, making monitoring easy.