Edited by damianipaolo, some rights reserved (CC BY-SA)
Photo Credits
- 1. (c) Mike Leveille, some rights reserved (CC BY-NC), uploaded by Mike Leveille
- 2. (c) Peter Trimming, some rights reserved (CC BY)
- 3. (c) Yersinia pestis, some rights reserved (CC BY-NC-SA)
- 4. (c) Austin 0201, some rights reserved (CC BY), uploaded by Austin 0201
