Sussex University researcher Karen McComb has found out it's really true elephants never forget.
She's studied African elephants and discovered mothers recall who they have met in the past.
This enables them to distinguish friend from foe and not waste time in protecting themselves and their families if the newcomers are benign.
It took her and a team seven years to study in depth the behaviour of 21 elephant families in Kenya.
While elephants remain a threatened species, work such as that of Dr McComb is important in helping us to understand the way they behave and react.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article