re: Animal in my wall

Lots of experience unfortunately….

In general if noise in middle of night is rat… if in evening or early morning when sun starting is a squirrel..

As op have said if a squirrel try to find and close hole in daytime to prevent squirrels going back in to sleep at night… if rat.. sorta stuck till leaves or dies….
Squirrels typically enter above ground.. under eave especially if second story.. will chew a hole in soffit especially where roof meet..corners…
You will probably not trap anything on attic.. but if able ….throw poison blocks ( those green chunk) … around in attic… you can stick your head into attic and throw them around and into corners… the rodents will find them…

If a squirrel you can set a live trap if you want.. if a rat you can buy little houses that you put the green chunk poison in and only small rodents can get into it.. suppose to be dog and child proof but I am to scared to use them in an area with kids and pets..
the poison is designed to make them thirsty and they will leave the house and go look for water and die ( or a drip pane in attic)….

If they die in wall.. yeah smell will peak for a few days.. may get a few flies but the nastiest stuff will be behind the wall a go away.. if in a ceiling space like between second/first floor.. probably will need kilz and touch up paint..

Sounds disgusting but is life in areas with nature and lots of trees.. not the end of the world..

If an animal can get his skull in he can probably get through the hole/ crack.