Stridulation is

Options

A. Gate of crickets
B. Respiratory movement of grasshoppers
C. Harsh shrill sound of crickets and grasshoppers
D. Copulatory dance .

Answer

**Step-by-Step Solution:**

1. **Understanding Stridulation**: Stridulation refers to the act of producing sound by rubbing certain body parts together. This is a common behavior in various animals, especially insects.

2. **Identifying the Context**: The question provides multiple options related to stridulation, specifically mentioning crickets and grasshoppers, which are known for their sound production.

3. **Analyzing the Options**:
- **Gate of cricket**: This option does not relate to sound production.
- **Respiratory movement of grasshopper**: This option also does not pertain to sound.
- **Harsh shrill sound of cricket and grasshopper**: This option directly refers to the sound produced by these insects through stridulation.
- **Copulatory dance**: This option is unrelated to sound production.

4. **Conclusion**: Based on the analysis, the correct answer is the third option: "harsh shrill sound of cricket and grasshopper." This aligns with the definition of stridulation as it specifically describes the sound produced by these insects.

**Final Answer**: Stridulation is the harsh shrill sound of cricket and grasshopper.

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