Why are open drains a concern?

Explanation

### Step-by-Step Solution:

1. **Definition of Open Drains**: Open drains are channels that carry wastewater and stormwater away from urban areas. They are not covered and are often found in streets and open spaces.

2. **Hygiene Concerns**: Open drains are considered unhygienic because they can accumulate waste, debris, and stagnant water, leading to unsanitary conditions.

3. **Breeding Grounds for Pests**: These drains serve as breeding grounds for various pests, including flies and mosquitoes. The stagnant water in open drains provides an ideal environment for these organisms to reproduce.

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