Signs of a spider infestation in an Alexandria warehouse may include the presence of webs, egg sacs, and shed skins in corners, ceiling rafters, and storage areas. You may also notice an increase in spider sightings, particularly of species such as black widows or brown recluses. Spiders are attracted to warehouses due to the abundance of prey and sheltered areas, making regular inspection and proactive pest control measures essential for preventing infestations.