If ice were more dense than water, it would freeze and sink over and over until the entire lake was frozen. ... This same process occurs in the fall as the surface water cools and becomes more dense; it will sink and cause the same movement or turnover of the lake's water.
That is called Urogenital myiasis which is a parasitic infestation. These flies are in the Diptera species group and the cause of this myiasis is from the eggs and larvae of this species (fly).
Let me know if you need further info.
- Dotz
Answer:a
Explanation: because naturally it occurs anytime it wants to