For years, one of the earliest signs of the spider season is the appearance of spider silk criss-crossing these metal signposts around campus. I rarely see any of the animals making the silk — they tend to hide in the holes that puncture the posts. But today I spotted one hanging out in a visible place! They are spiders in the subfamily Theridiinae, probably in the genus Theridion. I do not know why they favor this one peculiar habitat. These black metal posts get really hot in the sun, so these spiders must like it hot.

They have quite pretty patterns on their abdomens.