Object of the Month – September 2022

Harvest Mouse Nest

The Museum’s ‘Object of the Month’ provides an opportunity to explore interesting and unusual objects from our stores. 

To celebrate harvest time our ‘Object of the Month’ for September is the nest of a Harvest Mouse, Micromys minutus, made of woven grass. It was found in a clump of Knotgrass at Sweetings Meadow nature reserve, near Thaxted in 1999. The Harvest Mouse is Britain’s smallest rodent. Weighing only 4 to 6 grams it is light enough to climb grass stems and reeds, using its paws and long prehensile tail to grip the stalks.

This is our only mouse able to build nests by weaving living grass leaves together. In summer and autumn, the mice live above ground in camouflaged nests. Breeding nests are spherical and up to 10cm diameter in size to accommodate litters of two to eight young. Single mice build smaller, less robust nests up to 5cm in size. A Harvest Mouse survey in Essex found nests in the grass of roadside verges that bordered arable fields and in reedbeds, ditches, field edges and hedgerows. The nests may be sited up to a metre above ground in dense vegetation, or in the base of a tussock of grass.

Visit the Museum in September to see the Harvest Mouse nest on display, together with a photograph of another mouse with its nest in a barn taken by a local wildlife photographer. You can also find some tiny Harvest Mice on the Natural History gallery.

Chosen by Sarah Kenyon, one of the Natural Sciences Officers at the Museum.

Harvest mouse nest SAFWM : 2001.180

Saffron Walden Museum ©