Woken up by the warmth?

Warm temperatures today seem to have awoken some slumbering creatures:

 

Eric noticed two small bats flying over our house tonight.  We had fun watching them between 7:45-8:00 p.m. and then they disappeared.  At that time it was ~67°F.  Sunset was at about 7:36 p.m. 

When I posted about bats in October 2013, Jules suggested that they might have been Mexican Free-tailed Bats (Tadarida brasiliensis).  The bats we saw tonight also appeared small with visible tails, but I don't have enough experience identifying bats to say which species this is.

Although it's challenging enough to photograph a bat in flight at dusk, I realized it could be helpful to include something else in the picture for scale.  There wasn't much around tonight, but here's an image with a redwood in the background: