Herb-Robert - Geranium robertianum

Pink flowers with 5 petals. Leaves are palmately divided into 3-5 lobed segments.

Freshly picked, crushed leaves have a strong odor that resembles burning tires. If they are rubbed on the body, the smell is said to repel mosquitoes. I suspect that the smell would repel just about any creature. The active ingredients are tannins, a bitter compound called geraniin, and essential oils.