Is it lady bird or lady bug?

you can call it whatever it's mostly named ladybird but now people call it ladybug because it is a bug and also ladybird because it can fly and has wings so people have different meanings and names for it so really just call it what makes you like it, it is also known as a lady beetle.

It depends where you're from. In general, Americans refer to it as "ladybug" and British as "ladybird." I personally prefer ladybug. Maybe it's because I'm American, but I generally call bugs bugs and birds birds.