There's no need for the spider to know what itself looks like. If it builds something that increases survival/reproduction, that trait will be selected for.

There's no need for the spider to know what itself looks like. If it builds something that increases survival/reproduction, that trait will be selected for. The spiders’ webs were crafted around face-height, near the trail This makes me wonder if it was selected for stopping humans from wrecking their webs! It would explain why the decoys look like spiders, to humans.