Crazy dog?

The last few days my dog Pepper has been acting odd.  She has been staring at the wall like there is something on it.  She will even jump on the wall like she is trying to get something.  She has done it in three different locations of the house.  Of course it always happens in the middle of the night.  She can't pull this crap during the day.  I have never found anything, but it makes me wonder what she sees or hears to be acting so nuts.  Last week I found a scorpion on the wall in my kitchen.  I have been freaked out since.  One night there was a huge rat on my patio.  After those two incidents, I am petrified about what could be lurking in my house driving Pepper crazy.  Rowdy doesn't seem to be too concerned about whatever it could be so I am hoping Pepper is just nutty.  I have to think that otherwise I would lie awake at night wondering what is crawling in the walls of my house.  Let's just say I am not all that thrilled with the insects and rodents of South Texas.