High water makes the snakes move and the rats too. You can have rats in you home or other hiding places outside and not know it. They only move at night. The snake in your photo is going up to the top and he can smell rat piss and will move in on it for a meal. You might want to set out one rat trap and if you get one then you have more than one. I live in town and everybody keeps there grass cut and yards clean and my dogs still kill rats every now a and then. Rats are everywhere
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Maranatha 
Mat 7:14 Because strait is the gate, and narrow is the way, which leadeth unto life, and few there be that find it.