Venomous Water Moccasin or

Beneficial Non-Venomous Water Snake?

Adam Grayson

Have you ever seen a water moccasin?

Do you know how to properly identify the snakes you see in the field?

It never ceases to amaze me, how many people I talk to that say they have seen water moccasins frequent their lakes and ponds. But this assumption is a gross misidentification. Snakes most commonly mistaken for the dangerous water moccasin are other harmless, and beneficial, water snakes of south Florida.

While there are several species of water snakes found in southern Florida, the most common are the banded or southern water snake (Nerodia fasciata) and the brown water snake (Nerodia taxispilota). The banded water snake reaches an average length of 3 feet and can be identified by it’s stout body, keeled scales as well as a yellow-brown color, surrounded by a darker brown pattern down its body. This feature is more apparent in the young and usually fades with age. The brown water snake looks more like a water moccasin then its southern cousin. It is larger in size (reaches over 4 feet), heavier bodied, semi-triangular shaped head and has darker coloration. The two snakes are often found together, and they help keep rodent and amphibian populations at bay.

On the other side of the spectrum, the water moccasin (Agkistrodon piscivoris), also known as the cottonmouth, is a venomous, thick bodied pit-viper that is also found in the wetlands of Florida. While not nearly as common as the water snake, this dangerous south Florida denizen is still found in both rural and residential areas. Although this snake is known for its aggressive behavior, it would much rather be left alone than attack a person. The cottonmouth reaches lengths exceeding 5 feet, but are usually between 3 - 4 feet. It is thick-bodied, but more so than the non-venomous water snakes and has a noticeably triangular head, which is much wider than its neck. The coloration of the water moccasin is contrasting bands of a light tan with white on a forest brown with grey. The bands are lateral and fade with age. There is always the tell-tale sign of the face markings which consist of off-white lines on the top of the head and mouth, with a dark line behind the eyes and a vertical pupil.

Here are a few tips to properly identify these snakes when encountered in the field. If seen in the water, water moccasins always swim with their heads well above the water, while the harmless snakes usually dive into the water for escape. Water moccasins carry their heads off the ground at all times, usually cocked in a 45 degree angle.

The best advice I can give you when you encounter a snake in the wild and you are unsure of the species, is to LEAVE IT ALONE! If you know you have a cottonmouth in your work area and you feel that it may be a threat, use a large stick (at least 1.5 times it’s length) and pick the snake up mid-body and relocate it. If it begins to squirm away, remember to use the stick to manipulate its body away from you, if there is no other alternative . In most cases, the snake will try to remain hidden from you and remain un-aggressive, if unmolested. Now, keep in mind, most wild snakes are aggressive when threatened, whether they are venomous or not, so just let them have their space and they will be more than happy to give you yours!!