How to catch a monkey
They seek her here, they seek her there, but so far the last of the escapees from the Belfast Zoo break-out remains elusive.
In all, six monkeys jumped the electric fence and made a break for freedom.
All but one have now been accounted for but the search for adult female macaque "Roxy" goes on.
Michael Griffith is the vet in charge of the operation to find the missing monkey.
He hopes Roxy will return on her own as several of the others that escaped did, but says the team at Belfast Zoo is ready for action if the monkey is spotted.
"If a call comes in, whoever is available goes straight away to try to get a sight on the macaque. That's the most important thing for us," he said.
"Once it's seen we want to keep visual contact with it, so one or two people go straight away.
"We've a van sitting ready with all our capture equipment and our anaesthetic equipment sitting ready to go. We either take that or leave it for the people coming behind us."
One of the theories is the monkeys may have been "spooked" into jumping the fence.
Mark Challis, manager of Belfast Zoo, said: "When we first went up there to check, they seemed slightly spooked and so we have a suspicion that maybe a fox or something happened and maybe spooked them - but we can't be 100% sure.
"They are tough little monkeys and a few days out in the wilds of Cavehill won't do her any harm."
Mr Challis confirmed that security of the enclosure where the escape took place would now be reviewed.