What is a group of bears called?

A family. Bears are solitary (black, polar, brown bears (including the grizzly and the Kodiak) -- I'm not sure about Asian bears.)

The only time you will find them in groups is when you see a mother with cubs, or a male and female mating, or two males fighting for territory.

P.S. The notion that each species has a special name for a group -- e.g. 'a parliament of fowls' -- comes from a Victorian parlour game, in which people tried to think of funny names for a group of animals.

Some caught on because they were so apt:

'a kindle of kittens'
'a pride of lions'
'a quarrel of rooks'
'an exaltation of larks'.

Some never caught on:

"a skulk of foxes"
"a bloat of hippopotamuses"
"a prickle of purcupines"
"s shrewdness of apes".

Within that convention, however, it was 'A sloth of bears'.

But it has no roots in biology, or in English, for that matter, except as a game.

Thanks for the info