Squirrels are categorised into three main subfamilies:

Squirrels belong to the family Sciuridae and have a rich evolutionary history that dates back approximately 36 million years. They are thought to have evolved in North America and later spread to other parts of the world.

### Early Ancestors

The earliest known squirrels were small, tree-dwelling creatures that lived in the Eocene epoch. Fossil evidence shows that their ancestors resembled modern-day tree squirrels. Over millions of years, they adapted to various environments, leading to the diversity of species we see today.

### Evolution and Adaptation

Squirrels are categorised into three main subfamilies: 

1. **Sciurinae** – tree squirrels, which are proficient climbers.

2. **Xerinae** – ground squirrels, known for living in burrows.

3. **Ratufinae** – flying squirrels, capable of gliding between trees.

Their adaptations, such as sharp claws for climbing and a varied diet, have allowed them to thrive in different habitats worldwide.

### Cultural Significance

Throughout history, squirrels have been seen in various cultural contexts. In Native American folklore, they are often seen as symbols of preparation and resourcefulness. In literature and popular culture, squirrels are frequently depicted as mischievous and clever characters.

### Modern-Day Squirrels

Today, squirrels can be found on every continent except Australia and Antarctica. They are highly adaptable, frequently seen in urban settings, and play significant roles in ecosystems by dispersing seeds and aiding in forest regeneration.

In summary, squirrels have a fascinating history of evolution and adaptation, demonstrating their lively presence in both natural and cultural landscapes..