Scientific name of horse is Equus caballus. Learn about its classification, types, and equine evolution facts.

Headaches fall into two groups: primary headaches (the headache is the condition) and secondary headaches (a symptom of another problem), with episodic and chronic patterns. Common headache types have ...

Discover all you need to know about gray whales, including what they look like, how big they are, lifespan and where they live.