There are several places in the Moscow Zoo where you can see invertebrates:
Insectopia - the main exhibition of arthropods (mostly insects, but also arachnids and myriapods, some molluscs and worms are present also).
Birds and butterflies exhibition - placed in the same building with Insectopia. Several species of butterflies are housed in special enclosures along with some tropical non-insectivorous birds.
Exotarium - leafcutter ants and various aquatic invertebrates (crustaceans, echinoderms, molluscs, cnidarians).
The Wonderful world of reptiles - small exhibition separated from main Reptile house. There are several invertebrate species (particularly this tarantula is housed on the exhibition).
Arachnomania - exhibition of arachnids and other predatory arthropods. Currently avaliable only for excursions.