[cypher]

Do you have any idea if he's still in the room where he escaped or do you think he got out of there? Robos are so tiny he could slip through the tiniest of gaps but they do often come back so don't give up hope.
Setting up some kind of bucket trap is usually the best thing, a bucket might be a bit big for a robo but the idea is to use a container they can't climb out of, make some steps to get in, books or something would do, put some substrate in the container for a soft landing & some food or favourite treats & also put a little on the steps to tempt him in.
On hard floors you can put flour down & watch out for little foot prints, if he's still around that can give you an idea of where he might be.
Good luck, hope you do get him back.