Give one example of natural insecticide.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for an example of a natural insecticide. An insecticide is a substance used to kill or repel insects that can damage crops and grains.

2. **Identifying Natural Insecticides**: There are various types of insecticides, but the question specifies "natural" insecticides, which are derived from natural sources and are generally less harmful to humans and other vertebrates.

3. **Example of a Natural Insecticide**: One well-known natural insecticide is **neem**. Neem is derived from the seeds and leaves of the neem tree (Azadirachta indica).

4. **Properties of Neem**: Neem is considered effective against various harmful insects that damage crops. It is non-toxic to vertebrate animals, including humans, making it a safer alternative to synthetic insecticides.

5. **Conclusion**: Therefore, an example of a natural insecticide is **neem** (also known as margosa).

---