The Red Spotted Ant Mimic Spider acts like an ant to gain better positioning when attacking prey. It walks on its back 6 legs while raising the front pair as if they were antennae. This behavior relaxes other ants and insects into thinking the spider's presence is nothing to worry about. It allows the spider to get close to its prey, making it easier to kill and eat.
Adults spin sacs for themselves to rest in. These silken sacs are hidden near anthills or colonies somewhere either in a leaf, in bark cracks or on a node (where a new branch or tree starts growing). They can be found in a variety of habitats including woods, under stones, on shrubs or in parks.
Females use their spider silk to wrap eggs in a sac. They then attach the shiny egg sac to a rock or stone for safe-keeping. Spiderlings overwinter and hatch in the spring, leaving their siblings to find their own way.
Common name: Red Spotted Ant Mimic Spider
Scientific Name: Castianeira descripta
Adult Size (Length): 5mm to 10mm (0.20in to 0.39in) COMPARE
Identifying Colors: black; red; white
General Description: hairy, biting, venomous
North American Reach (Though Not Limited To*): Alabama; Alaska; Arizona; Arkansas; California; Colorado; Connecticut; Delaware; Florida; Georgia; Hawaii; Idaho; Illinois; Indiana; Iowa; Kansas; Kentucky; Louisiana; Maine; Maryland; Massachusetts; Michigan; Minnesota; Mississippi; Missouri; Montana; Nebraska; Nevada; New Hampshire; New Jersey; New Mexico; New York; North Carolina; North Dakota; Ohio; Oklahoma; Oregon; Pennsylvania; Rhode Island; South Carolina; South Dakota; Tennessee; Texas; Utah; Vermont; Virginia; Washington; West Virginia; Wisconsin; Wyoming; Alberta; British Columbia; Manitoba; New Brunswick; Newfoundland and Labrador; Nova Scotia; Ontario; Prince Edward Island; Quebec; Saskatchewan; Mexico
* Keep in mind that insect reach is not governed by lines on a map and therefore may appear in areas/regions/states beyond those listed above.