Can animals see ghosts?

Can animals see ghosts?

The evidence;

1) My cat was sat in the corner staring at the corner of the room. She must have been staring at a ghost.

2) My grandad's dog used to go mental when he walked past part of a building at an army barrocks. He later found out there had been an archway there where people were hung. The dog must have been seeing ghosts coming through the bricked up archway.

So its conclusive right?

-- Posted from my iPhone