I spent this summer conducting ecological research with snakes in NC. One of the primary duties of my job was scale clipping and pit-tagging every snake that was large enough to "take" it. While I was there, this included rough green snakes, black racers, kingsnakes, black ratsnakes, and hognose snakes.

My personal rule of thumb came to be that the snake had to be at least 4 times as wide as the syringe, which is about 1.5 to 2 mm wide. The smallest snake I personally tagged was thus a juvenile black racer that measured about 20 inches. The smallest snake I SAW with a pit tag was a juvenile hognose that was tagged in April. We recaptured that snake in June and it had doubled in weight and grown to 14 inches or so (note thats after only 2 months). This not only illustrates how well that snake was feeding, it also illustrates how well snakes can survive IF the tag is inserted properly.

Its my opinion that any snake species in Ohio that was 18 inches could survive a pit tag if done properly. I don't personally know what the recapture rate is for pit tags but you can't really judge that as a mortality rate unless you've tagged a significant proportion of the total population, which is very very difficult to estimate in the first place. The bottom line is, larger snakes will survive just fine, smaller snakes may have trouble but should ultimately survive.

So what is the proper method? We would place the tag approx 2/3 down the body between the head and cloaca. This avoids most of the major organs besides the digestive tract and ovaries/testes. The tag is inserted into the end of the syringe. You then pierce between the belly scales and push it in only as far as the cutting edge (and orifice) of the syringe (do this with the orifice facing out). Obviously you also keep the tip pointed up the body and not inward toward the major organs. Once it pierces the skin its in the body cavity and you should turn the syringe 180 degrees so the orifice is facing into the snake. Push the plunger and hold your thumb over the shaft of the syringe as you pull it out.

When done correctly, no blood or bodily fluid should appear. Now I practiced this technique many times on DORs (and without the tag) before I tried a real snake. You need to feel confident in your hands to do this otherwise you can go too deep or scratch the body cavity with the syringe point. Either is bad for the snake. I also want to point out that you really should have someone teach you this in person before you go out and try it on your own using just my instructions. It is easy to do, but its MUCH easier said than done. This is why I practiced on at least 10 DORs before I attempted a live snake- all with supervision.

Another thing I want to mention. We also performed surgeries to implant radio transmitters in adult ratsnakes. The ratsnakes heal in about a week or so but can easily be released the day after surgery. Few snakes have died as a result of the surgery and it usually happens when surgery is done in late fall and temperatures are not warm enough for the snakes to heal adequately. Now here's the kicker. One of the snakes we did was thin and so I left 2 f/t mice in its cage immediately after surgery. The mice were gone the next day. This is a wild snake eating 2 mice immediately after major surgery in the body cavity. I have no idea if it regurged or not but the point is, after PIT-tagging your snake it should eat within a week. Even if the cage isn't sterile clean the snake shouldn't have any kind of infection.

Anyhow, I hope this helps ease your fears about the PIT-tagging business. I'm sure that local veterinarians or university staff would be willing to help teach the proper methods (if asked nicely lol).

Good luck!
Van