When they have their mouth open and fangs bared, it is time to leave it all, right there. Glad you looked down. because they do not back down.
One of our favorite bass fishing areas was adjacent to some Spring Bayou farmland that had been reclaimed from the swamp. Before the spring rains started, the farmers would build a dirt access road across an old slough, which they abandoned after the rains started. When the rising water reached the top of the road, it would spill over into the slough carrying earthworms, bugs, crawfish, etc. to the bass waiting below. Eventually the water would wear away the weakest part of the road, and there would be a sluice cutting through the parts of the road left out of the water. I pulled my boat up to the sluice intending to get out and fish from the road. Something told me to look down, and there was a huge black cottonmouth with mouth open and fangs bared. I almost leaped over the boat in my haste to get away.
They love that running water. In the rice fields where the water runs over a plastic gate from one levee to the next was the favorite place for the cottonmouths. I couldn't raise any rice in a 5' diameter around the gates because my help would beat it down with a shovel going up to check a gate.
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