Museum’s exposition starts with the most primitive animals: sponges, cnidarians, worms, molluscs, echinoderms, and arthropods. More than 4 thousand of invertebrate animals are exhibited. In 2016 Vykintas Matuzevičius donated a collection consisting of more than 10 thousand shells.
About ten thousand insects belonging to more than 2, 600 species are presented in the 24 stands of this hall. Besides the systematic exposition of insects, the zoogeographical distribution of butterflies is also presented. Australian, Ethiopian, Indomalayan and Holarctic regions are represented by the most colourful and most beautiful specimens of the Lepidoptera order. Separate stands display the most spectacular and colourful beetles in the world. Also, visitors can see two dioramas (“Useful insects of Lithuania” and “Insects in various biotopes”), a collection of wild Lithuanian bees (more than 140 different species), and a collection of Lithuanian butterflies (more than 400 species, gathered and donated by V. Bačianskas).
The representatives of three animal classes are displayed: fishes, amphibians, and reptiles. The collection contains more than 7 thousand exhibits. The exposition contains about 500 exhibits. The most impressive exhibits are coelacanth, Atlantic sturgeon, swordfish, Indian python, caecilian, the only specimens of common sole and European hake caught in Lithuanian waters, sea turtles and crocodiles included in
the IUCN Red List of Threatened Species.
Traditionally it is one of the best-represented vertebrate classes in the museum. The collection contains more than 12 thousand exhibits; the exposition presents more than 900. stuffed birds and 600 eggs, belonging to 200 bird species. There are 12 dioramas in the exposition hall.
Visitors can see skeletons of prehistoric and currently living animals: skeleton parts of mammoths that lived in the territory of Lithuania more than 12 thousand years ago, horns of aurochs that wandered in our forests till the 16th century, skulls of woolly rhinoceros and the largest terrestrial mammal, the African elephant, some bones of the largest mammal in the
world, the whale. In the anatomical part of exposition skeletons and skull models of mammals, birds, reptiles, and fish are displayed.
About 90% of all mammal species living in Lithuania are presented. In total, 365 stuffed animals, 3 moulages, 23 skulls, 5 dioramas, and a biological group of wisents. 55 species of presented mammals are listed in the IUCN Red List of Threatened Species (Cheetah, Siberian Tiger, Polar Bear, Snow Leopard, Giant Anteater, Bornean Orangutan and others), 14 species are listed in the Red Data Book of Lithuania. The exposition contains a whole range of animal “champions”: the tallest animal in the
world (giraffe), the fastest animal (cheetah), the largest predator (polar bear), and the smallest mammal (pigmy shrew).
About 300 trophies both from Lithuania and the rest of the world are displayed. These are horns, stuffed heads, sculls, furs, and tusks. All the trophies are evaluated by the standard formulas for the measurement of trophies approved by the International Council for Game and Wildlife Conservation (CIC). One exhibit has been awarded the Grand Prix, 26 gold medals, 25 silver medals, 38 bronze medals. Most of the trophies
are the catches of Lithuanian hunters.