Backyard friend

When we first moved into our house we had problems with moles in our back yard.  They made tons of babies and really made a giant mess out of our lawn.  We tried everything to make them go away but they wouldn't.  Then last year they suddenly disappeared.  We suspected that we must have a snake in our yard that was eating them.  We finally found the snake at the end of the summer and it was really tiny, I think there are actually two of them.

Well the snakes survived the winter again and Bree found them the other day and, I have never seen our cat run so fast back into the house in all my life.  Can a cat really be afraid of a snake?  This morning it was out sunbathing so I snapped a picture.  Its grown a lot.

I took this one from the deck with my zoom, I was afraid it would run away if I got to close.

I walked up close to it and got a better picture.  Anyone know what kind of snake it is?  I appreciate it helping to keep our backyard rodent free.