Sorry but somebody asked. So here is your answer!

Blood itself does not have a smell, as it is odourless. However, when blood is exposed to air, it can produce a distinctive metallic scent due to the presence of iron in hemoglobin, which is the protein that carries oxygen in red blood cells.

This scent can be detected by our sense of smell and is often described as a "coppery" or "iron-like" smell.

The scent of blood can also be influenced by other factors, such as the presence of bacteria, which can produce a different odour, however we are not going there.