Sac Spider

Cheiracanthium mordax

Family: Miturgidae  ID: Koch, 1866

Habitat and Biology
The sac spider is another vagrant hunter. It makes a silken retreat or sac in which it rests during the day and may be used for moulting and egg laying. In nature, the spider's sac occurs under the bark of trees or amongst foliage. In buildings, the spider's sac is built behind cupboards, pictures etc. The egg mass is deposited in the sac, encased in silk and guarded by the female. The lifespan is not known but is unlikely to exceed two years.

Colour
Male: Similar to female but often slightly darker overall.
Female: Cephalothorax and legs pale brown, abdomen cream with darker longitudinal stripe on upperside.

Form
Small, stout-bodied spiders with slender legs; male has remarkably enlarged jaws giving it a rather unusual appearance.

Body Length
Male: 9mm
Female: 10mm

Web type
Does not build a web.

Bite
The bite of this spider may cause general symptoms including local pain and ulceration, nausea, faintness and headache.