Yeh definately go for it, I would say he likes you, if he seems keen to say hello to you lots then that positive, I would do the same in his position and I fancied you, he's trying to make converstaion with you 'cos he likes you IMO. Don't quite know how to ask him out/let him know you like him, putting myself in his shoes again, the best thing would be to ask him out, just say there's a film on/ do you wanna go to that new restaurant, corny I know but if he likes you he won't care at all just will be really chuffed that you like him too, and if he doesn't he will just be flattered that you found him attractive!
If you lack the confidence to ask him straight out right now just strike up convs with him when you're in there next....I can't find what I need/ do you reccomend this stuff? (though conversations about petfood aren't paticularly romantic so try and steer the topic onto music/something better if you can, better to just ask him out tho!)