Perhaps it had something to do with the prolonged drought we had endured. The diamondback was just a baby, and may have been wandering around looking for appropriate habitat in which to stake his claim. He never did attempt to strike. The guy on the right was shot while we were both in the water, and he seemed more curious than alarmed. He didn't threaten or try to retreat while I was shooting him.
Some pigmy rattlesnakes.
In the middle is a mother with one of her neonates. Once neonates shed, they part company with their mother and are on their own. The snake on the right had crawled a foot or two up into some twigs to escape the rising water during one of the regular floods in the hammock where they live.