They really do have long memories! Research by the
Massachusetts Institute of Technology has shown that elephants have
very long memories, large brains and are highly emotional.
Orang-utans are the cleverest of non human primates and can perform
complex tasks such as opening doors by choosing the right key from a
bunch of keys. Squirrels have a brain proportionally 1.5 times bigger
than humans and can remember where they have buried 10,000 nuts!