Confused about my horse?

i have a 2 1/2 year old mustang TB mix i moved her to my house about 2 weeks ago she is alot happier then she ever has. she keeps walkin back and forth at night really bad. im not sure why she could be doing this. im not sure if something is in the woods upseting her. and she freaks out when i put bug spray what could i do to make her not scared to get spayed with it?