If I create two morphs like this:

|p c|
p _ RectangleMorph new.
c _ RectangleMorph new top:100.
p on: #mouseEnter send: #value to: [Transcript show: 'parent'; cr].
c on: #mouseEnter send: #value to: [Transcript show: 'child'; cr].
p addMorph: c; openInWorld.

and I mouseEnter the child (the lower morph), the parent obviously
receives a mouseEnter first, probably because I did enter its
territory. 

Is there a way to let only the child receive a mouse enter and the
parent only if I enter its visible territory ?