She's a biter 😭

A little help would be great. I have 2 girls a 3 year old and a 1year 8 month old. My youngest is a biter. And I mean she's so bad with it!

She has bitten my eldest more times than I can count. Normally it's when my eldest has snatched a toy from her or is annoying her so I can understand why she does it,as its our of frustration. But it obviously doesn't make it right!

Does anyone know a way to stop her biting. I've done the shouting, making a fuss of her sister, time out, ignoring it. Nothing seems to go in that it's wrong!

I know she's only a year and a half old, But she has understanding and Its at the point now that her sister is getting scared around her as 'she doesn't want to get hurt' and to heat that is heartbreaking 💔😭

I have read on line about biting them back and I'm totally against that, as I am smacking my children so please don't suggest that please. Has anyone got any ideas on how to stop it 💔

Photo of today's newest mark 😭💔