Generally speaking, the most common types of poisonous spiders you’ll encounter are the brown recluse and black widow. The black widow is clearly recognizable from the large red hourglass-shaped marking visible on their abdomen. The brown recluse can be slightly more difficult to identify, but it’s certainly possible to do. Look for violin-shaped marking on top of the thorax, as this is their most distinguishing feature. If you encounter a spider in your home that you believe is poisonous, exercise extreme caution. Consider contacting Absolute Pest Control for expert assistance.