Other than for having it on hand when nature calls, toilet paper can serve another important purpose for hunters. I use TP for blood trailing, too, and keep some in my backpack.
When tracking a wounded deer, mark the blood trail every so often by leaving a piece of toilet paper in the brush along the trail. This will help you find the trail if you somehow get off track.
Toilet paper is also biodegradable, and it will eventually dissolve.
Editor's Note by Tim H. Martin
Bryan's TP tip is one I've used for many years. I keep toilet paper — a lot of it — in a Ziploc bag in my backpack, and I keep an entire roll in my truck at all times.
When blood trailing, I like being able to stand back and see the general line a deer has taken and get an idea of where it might be headed. The TP markers give me that ability. And if the blood is really sparse, I leave pieces right next to the droplets so no one will step on them.
By paying close attention to the path, intricacies and patterns of a toilet paper trail, you can learn a lot about the way a wounded deer travels.
TP will stay on the ground a long time, even if it gets wet, which is great if the forecast calls for rain.
Even if a blood trail is easy to follow, I leave TP on a blood trail if there's any chance of precipitation. Should it rain overnight, this saves me an easy-to-find path with which I can resume trailing the next day.
So keep toilet paper zipped tight in your backpack with extra in your hunting vehicles, and don't be afraid to bring a lot. There are many instances when you simply can't have too much TP, and I'm not just talking about blood trailing!