Do ants 'high-five'?

 

Spent a lazy hour sitting in April sunshine watching foraging ants, in constant transit to and from their nest in a big terracotta flower pot. Every time an outgoing ant met an incoming forager their stopped, head-to-head for a moment , to touch antennae, like the pair in the foreground here. Is this the ant-equivalent of a ‘high-five’? I’d like to think so, though it’s most likely colony recognition behaviour, border control, defence against potential invaders.