they just associate you with food, thats all any animal does, it only seems they like you, did you ever suppose a dog wants you to pet him, because he feels he is the best and most dominant animal in the house, therefore you better praise him!
there is truth in that but I don't think its entirely accurate, at least not with some mammals. dogs and cats and other similar mammals do form bonds with humans, even ones that don't supply food to them. all organisms are selfish in their connections with others but its not always about food.