This species is endemic to western areas of Continental Europe and the British Isles,[1][2] where it lives in the surface layers of the soil in moist habitats such as among leaf litter.
Allacma fusca is a large species of springtail with a dark brown globular abdomen; adults reach a length of around 3.5 mm (0.14 in).
The fourth abdominal segment bears an organ known as a "dens", and at the tip of this is a structure known as a "mucro".
[3] Invertebrates living among the soil particles in underground habitats often experience raised levels of carbon dioxide, which tends to increase with depth.
Researchers have found that the surface-dwelling Allacma fusca can tolerate a 10% level of carbon dioxide for a few hours while in contrast, the springtail Folsomia candida, which lives deeper in the soil, can survive under the same conditions for more than six weeks.