Follow blood trail is an objective in the Side Quest, Wildlife Conservation in Borderlands 3
- Head to the North and across the bridge here over to the West toward the cave to the Southwest beyond it, with the blood on the ground.
- Follow this cave inward to arrive in Unused Escape Tunnel.
- Go forward through the tunnels to reach the first chamber inside the cave, just past the dead Psycho on the ground.
- Deal with the few Varkid Larva that are in the cavern.
- Head to the Southern shutter door and attempt to use the nearby switch to open the door.
- It is stuck, but there is a way through yet.