In just two weeks, students will stream back to school. And while all of us know that — coincidentally — fish travel in schools, did you know that a group of hippopotami is called a bloat? We consulted with our friends of the Encyclopedia of Life to find out other animals that travel in unusually named groups. Below, find out which animals congregate in a tower and a parliament, as well as an unexpected mammal that also settles into schools.

A murder of crows
Large, intelligent songbirds, members of the genus Corvus occur on all the continents except for South America and Antarctica. Larger forms are called “ravens,” most are called “crows” and the two smallest — in their own sub-genus — are called “jackdaws.

A school of dolphins
Long-beaked common dolphins usually travel in social groups ranging from 100 to 500 individuals. But they have occasionally been seen in larger schools of thousands.

A dazzle of zebras
Mountain zebras have what’s called a polygynous mating system. They form small breeding herds that consist of one adult stallion and 1 to 5 mares with their young. Breeding herds remain stable over many years and mares usually remain in a herd for life.

A bloat of hippos
Hippopotami live in groups of 15 or more animals. These groups are primarily females and their young, headed up by a dominant male.

A tower of giraffes
While giraffes are usually found in groups, the composition of these groups is more fluid than in other social animals.

A parliament of owls
We normally think of a lone owl, howling on a branch in the foreboding night. But, on occasion, owls do team up. When that happens, it is called a “parliament.”

Photo credits:

• Long beaked dolphin: World Register of Marine Species
• Corvus: J.M.Garg
• Mountain zebras: David Patterson
• Hippos: Paul Maritz
• Giraffes: Jamin
• Owl: Edd Deane