Bats Human Harvest is a 2007 SciFi Channel original movie, directed by Jamie Dixon, and starring David Chokachi, Tomas Arana, Bill Cusack, and Melissa De Sousa.
Most of the force was killed during the mission along with other groups of rebels, and only four members of Delta force, including Russo manage to survive. Russo, the leader, finally discovers Walsh, who has become immune to the bats by injecting special chemicals into him. Russo kills the doctor and get back to the rebel camp, using a highpower microphone to send out noises to lure the bats back to the camp, where he ignites the fuel tanks and blasts the camp, killing all of the bats except one that survives at the end of the film, flying off a farmers wagon. Russo and the other survivors, Downey, ONeal, and Katya, escape.
Source: Wikipedia