What is heat period?

Explanation

**Step-by-Step Solution:**

1. **Definition of Heat Period**: The heat period, also known as the estrus phase, is a time when female non-primates exhibit sexual receptivity and readiness for mating.

2. **Occurrence in Non-Primates**: This period is primarily observed in non-primates such as dogs, cats, tigers, mice, rats, and sheep. Unlike primates, these animals do not have a menstrual cycle.

3. **Estrous Cycle**: In non-primates, the reproductive cycle is referred to as the estrous cycle, which includes the heat period as one of its phases.

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