1. Heat oven to 425 degrees . Place flatbreads on 2 baking sheets and top with pesto. Divide tomato slices among flatbreads. Slice cheese into thin strips; place on top in the shape of a spider web.
2. Bake flatbreads at 425 degrees for 7 to 9 minutes, until cheese melts and flatbreads crisp up. Cut 3 olives in half lengthwise. Use for bodies of spiders. Cut one end of 6 olives for spider heads. Halve remaining olives lengthwise and cut into strips for the spider legs. Assemble spiders on top of cheese webs. Cut flatbreads in half just before serving.