Ellie, Jo,
the three holes on the top of a coconut are totally
natural. When the coconut sprouts, the new stem will
grow through one of the holes. And this hole is always
softer than the other two. I can be opened easily
with a knife. OTOH tampering is very easy, one only
has to find the soft hole with a needle and inject
sugar solution through it.
BTW: The pagode coconuts should be stored on the
tipped side and quite cool, about 10 C and dry, then
they will stay good longer.
-Karl