A minor episode not
important in the mythology, written by Steven
Delarnatt. The reason why the aliens would want to make a Noah's Ark is
unclear, but this isn't the point in this ecology-oriented episode.
Also, why would they use animals in zoos instead of animals in the
wild? They could draw much less attention. Even less so if they'd
return the animals exactly where they
took them. Invisibility was introduced in 1X09: Fallen Angel, seen later
on 7X22: Requiem;
here it seems
invisibility is an ability that can be given from the ETs to anyone and
anything, including living animals. One shouldn't look a complete
coherence with the rest of the mythology with this episode which is entertaining nevertheless.