Arachnid · GBIF taxon 2164198
Northern Yellow Sac Spider
Cheiracanthium mildeiAlso known as Long-legged Sac Spider, Mild's Sac Spider, Yellow Sac Spider
Northern yellow sac spiders are agile nocturnal hunters that do not spin webs to catch prey, instead roaming foliage and interior walls after dark. During the day, they rest inside flattened silken tubes constructed in leaf folds, wall corners, or crevice spaces. Pale yellow to translucent greenish in tone, these adaptable arachnids frequently cohabitate with humans in temperate regions worldwide.
NocturnalSynanthropicPredatory
1 / 7Not EvaluatedIUCN status
Diet & prey
- Flies
- Leafhoppers
- Moths
Predators
- Centipedes
- Lizards
- Birds
threatsPesticide application and direct human mortality
habitatsHomes, gardens, orchards, and low vegetation
life Span1 to 2 years
Conservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →Not Evaluated
Encounter riskVery high
- Low
- Moderate
- High
- Very high
Delivers a painful bite if squeezed or trapped against skin; gently relocate using a cup.
Injects mild cytotoxins that cause localized stinging pain, redness, and minor swelling lasting a few hours.
- How to recognize a risky encounter
- Look for a pale yellow-green translucent body with long front legs and dark brown tarsal tips.
- What to do
- Do not handle with bare hands; use a stiff paper card and glass jar to move out of living spaces.
Responsible observation
- Relocation: Place a container over the spider and slide paper underneath to transport it outside.
- Prevention: Seal window gaps and outdoor light entry points to deter prey insects from drawing spiders indoors.
- Bite First Aid: Wash bites with soap and water and apply a cold compress to reduce localized swelling.
Competitor Frequent Companion 
Close Relative (c) Ilona, some rights reserved (CC BY-SA), uploaded by Ilona · cc-by-saClose Relative
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