Do Flares Even Work?-A Quiet Place The Road Ahead Ep 14

On the hunt to turn the sprinkler system back on, I ran into an issue with how steep some of the board placements were and if they would slip out from underneath you when walking on them. There were a few the were questionable. Also, do the flares attract the creatures or not? I threw 3, 2 of them did not attract and 1 did. What is up with them?