Shrub
Birds used to peck the tops off milk to get to the cream. Now milk is homogenised the cream is no longer at the top so they don't do it!
My (whole organic) milk isn't homogenised. It is very rich and creamy especially in late spring/early summer months and still has a thick layer of cream on top.
Supermarket milk is generally homogenised I've found - even most of the organic offerings.
Strangely though I've not had a bird peck the lid for years!