Sniffs
My hooman should know something. In fact, all hoomans should know it. If you pass something in front of me - and most cats - it will be sniffed. It's my job to check it out. If my hooman comes up to me, he will be sniffed too. It doesn't matter if it's the first or the twentieth time he's come up to me that day - sniffs will take place. And it doesn't matter if he only came up to me two minutes ago, and got sniffed then - there will be more sniffs. He could've been anywhere. He could've been near ham...or another cat...or an interesting-smelling hooman. Sniffs are absolutely essential. And please don't nose boop us, mid-sniff - very annoying.