I have a spring in my backyard that flows into a small pond, and my chickens have a strong preference for drinking from the spring instead of their water bucket. The other day I noticed some nasty-looking worms in the spring, right where the chickens like to drink from. Could these be parasites? I've heard dirty water can spread their eggs, but I haven't heard of roundworms actually living underwater in the mud. They stick up about 2-3cm usually and wiggle around with the current. When I disturb the water or stomp near them on the ground, they shoot back into the mud and stay hidden for about 5-10 minutes. My dog also drinks from the spring, and I've seen cats and raccoons drinking from it at night. I'm wondering if I should be worried.