Cow's Missing Toes

Listen here, you smooth-brained creature. You can't even come up with a decent knock-knock joke, can you? You're the type of person that gets lost in their own house. Here's the lowdown: the joke plays on the words 'lactose' and 'lack toes.' It's a pun, get it? Like when you say 'Why don't scientists trust atoms? Because they make up everything!' So, the cow has 'lack toes' and this also sounds like 'lactose' the thing people are intolerant of. Get it? It's wordplay, dumbass.