Eucalyptus (I think not but maybeeeee)? As chipped bedding.

[Chickenman MAN]

So I've read that it's fine for chickens, but toxic to most mammals... BUT you really shouldn't use it because there is a disease fungi thing (cant remember the name) that may well be on it and would kill you hens very easily... so better safe than sorry... I won't be using it I don't think!