Field defects are places on arable land where crops do not grow, but bare soil or spontaneous communities of plants can be found. In previous years, we investigated naturally occurring field defects , but in a recent project we created artificial defects in cooperation with farmers. Such defects can be used as a measure to support biodiversity inside the fields. In our recent studies we demonstrated that field defects are not very important for invertebrates living on the surface of the soil (worms, rove beetles, millipedes and centipedes). These habitats become more important for groups of invertebrates that use plants as a food source or as habitat during their lifecycle (e.g. butterflies, bees, parasitoids, bugs or spiders). For these groups, field defects are more attractive than the surrounding crops. The importance of field defects is higher in the period when the surrounding crop has already flowered and dries up before harvesting (ripening).