We moved to Houston last March. I put a large pot with flowers on the patio, which happened to be right outside our bedroom window. I watered it pretty often. After about a week, I started hearing this strange chirp when I was in bed. I even told my husband that I wondered if the smoke alarm was going out! Then one day when I was watering the pot of flowers, this little green frog hopped out from inside the plants and started making that chirping sound. Mystery solved!
He's already back, because I just heard him the other day. Made me smile.