---
title: "Bull-headed sac spider"
description: "Trachelas pacificus — Insects & spiders. Trachelas pacificus is a species of true spider in the family Trachelidae."
canonical: https://animalchecklist.com/animal/bull-headed-sac-spider
last_updated: 2026-09-20
---

# Bull-headed sac spider

> Trachelas pacificus — Insects & spiders. Trachelas pacificus is a species of true spider in the family Trachelidae.

- Scientific name: *Trachelas pacificus*
- Category: `insects` (Insects & spiders)
- Habitats: `urban` (Towns & gardens)
- iNaturalist observations: 2584
- Wikidata: [Q2945954](https://www.wikidata.org/wiki/Q2945954)
- iNaturalist taxon: [298342](https://www.inaturalist.org/taxa/298342)

## Names

- en: Bull-headed sac spider

## Countries with the most observations

US (889), MX (4)

## Summary

Trachelas pacificus is a species of true spider in the family Trachelidae. It is found in the United States and Mexico, specifically Arizona, California, Nevada and Baja California. They are commonly found in houses, and adults can be found year-round.

Text: Wikipedia (en), CC BY-SA 4.0 — https://en.wikipedia.org/wiki/Trachelas_pacificus

## Photo

![Bull-headed sac spider](https://animalchecklist.com/img/animals/bull-headed-sac-spider/medium.jpg)

Photo: Diego Blanco · CC0 · inaturalist — https://www.inaturalist.org/observations/270147390

## Machine access

`GET https://animalchecklist.com/api/v1/animals/bull-headed-sac-spider?lang=en` — see [openapi.json](https://animalchecklist.com/openapi.json).