Which spider is this?

Answer

Dear Valerie,

Spiders are determined by their reproductive organs, the palps of the males and the epigyne (a plate on the ventral side of the abdomen) in the females. These details are usually not visible in photos. Only when it comes to a spider with a special color pattern such as the tiger spider, for example. can be determined with any certainty from a photo.

I suspect your spider is the Flat Orb Spider (Nuctenea umbratica). But she should actually be in a web. It is a typical nocturnal spider that makes its web when it gets dark and hides in a crevice during the day. A very harmless and useful animal!

Kind regards,

Rudy