Small rodent in back yard - on walls
Yesterday around 8:00 PM I was sitting my my pergola/gazebo (I put a redwood roof on it, and so I'm not sure it is still a pergola), and I noticed what looked like mice or kangaroo rats climbing on the fig vine growing on the wall between my house and the neighbor's (see photo below). They stayed in a group of four and walked along the vines near the top of the wall and did not seem interested in getting close to the ground. I've never seen them anywhere except in the vine, and the seem to have a humped back when walking. It was hard to see what color they were because they stayed deep in the foliage, but they seemed very slightly larger than regular mice.
What do you think they are? Should I do something to get rid of them? I also have alligator lizards in these vines, but I like the lizards and do not like the rodents. The neighbors have dogs, but I don't think that is enough to control the rodents. Is there a possibility that they will have a population explosion? Right now there are very few of them, and they seem to be active only in the evening and at night.