Fibonacci numbers are a sequence of numbers where each number is the sum of the two preceding ones, starting from 0 and 1. The sequence goes as follows: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, and so on.

Fibonacci numbers appear in many aspects of nature, including the growth patterns of some plants and animals. Here are some examples:

1. Sunflowers: The seeds in the center of a sunflower head are arranged in a spiral pattern that follows the Fibonacci sequence. The number of clockwise and counterclockwise spirals are usually consecutive Fibonacci numbers.
2. Pinecones: Pinecones also have spiral patterns that follow the Fibonacci sequence.
3. Nautilus shells: The chambers in the spiral shell of a nautilus also follow the Fibonacci sequence.
4. Bees: The number of bees in each row of a beehive also follows the Fibonacci sequence.
5. Human anatomy: The proportions of human body parts, such as the length of the fingers and the segments of the arms, also follow the Fibonacci sequence.
6. Music: Some composers, such as Debussy and Bartók, have used Fibonacci numbers in their musical compositions.
7. Financial markets: Fibonacci numbers are sometimes used in technical analysis to predict stock prices and other financial trends.

These are just a few examples of where Fibonacci numbers appear in nature and other areas.