r I
take care to remove some of those which are full and to replace them by
others that have not yet been used. Very few of the Bees decide to take
possession of these new homes, which differ in no particular from the
earlier ones; and even then they build only a small number of cells,
which are often mere attempts at partitions.

They want something different: a nest belonging to some one else. They
bore through the stopper of the inhabited tubes, a work of no great
difficulty, for we have here not the hard cement of the Chalicodoma, but
a simple lid of dried mud. When the entrance is cleared, a cell appears,
with its store of provisions and its egg, with her brutal mandibles; she
rips it open and goes and flings it away. She does worse: she eats it
on the spot. I had to witness this horror many times over before I could
accept it as a fact. Note that the egg devoured may very well contain
the criminal's own offspring. Imperiously swayed by the needs of her
present family, the Osmia puts her past family entirely out of her mind.

Having perpetrated this child-murder, the depraved creature does a
little provisioning. They all experience the same necessity to go
backwards in the sequence of actions in order to pick up the thread of
their interrupted occupations. Her next work is to lay her egg and then
she conscientiously restores the demolished lid.

The havoc can be more sweeping still. One of these laggards is not
satisfied with a single cell; she needs two, three, four. To reach
the most remote, the Osmia wrecks all those which come before it.
The partitions are broken down, the eggs eaten or thrown away, the
provisions swept outside and often even carried to a distance in great
lumps. Covered with dust from the loose plaster of the demolition,
floured all over with the rifled pollen, sticky with the contents of the
mangled eggs, the Osmia, while at her brigand's work, is altered beyond
recognition. Once the place is cleared, everything resumes its normal
course. Provisions are laboriously brought to take the place of those
which have been thrown away; eggs are laid, one on each heap of food;
the partitions are built up again; and the massive plug sealing the
whole structure is made as good as new.

Crimes of this kind recur so often that I am obliged to interfere and
place in safety the nests which I wish to keep intact. And nothing as
yet explains this brigandage, bursting forth at the end of the work like
a mo