The Urban Pantheist

I live in Cypress, Texas which is a little north of Houston. i live in a suburban development that is named Lakewoods Forest. It is an older development that maintained the trees when the houses where built about 20 to 25 years ago. It seems like the forest creatures have all stayed even after the houses where built. I see opossums, squirrels (by the dozens), more birds than you can imagine, and earthworms everywhere (dead on the road next to the curb and on the driveway all the time). If I see one while walking my dogs that is still alive, I will toss it back into the yard. Anyway, I was walking my dog this morning at about 5:30, which means it was still dark, when she stopped to smell something on the road next to the curb. She stayed there so long that I decided to see what was so interesting. I was shocked to find a Terrestrial Flatworm coiled around an earthworm in a life and death struggle. The worm did not seem to have a chance to live even though it was wiggling desperately. Since I had never seen this before and only seen the Terrestrial Flatworm once before in my yard on a water meter cover, I picked up the worms in the struggle with a clean dog poop bag. About 10 minutes later, after the dogs walk, I showed it to my wife. The earth worm had an area that was no longer covered by the flat worn but its skin looked red. I imagined that it was a reaction to the slim of the flat worm. About 2 minutes later there were a lot of small bubbles that looked almost like foam. The earthworm no longer moved and the flat worm was also still. They were still in the bottom of the bag and the bag was on my bathroom counter as I continued my morning routine for about 5 to 10 minutes. My wife excitedly brought my attention back to the bag because the flat worm was working it's way up the side of the bag. The earth worm had killed in and but it did not appear to use it for food. You could still see some of the small bubbles around it and heavy tint of Red color. I gave the flat worm to my next door nieghbor who studies snakes who referred to it as a snake but sent me this article. Thank you for your knowledge. I have one question. Should I be concerned about this worms existence in my yard to the point of poisoning for it?