AP Photo

Opening the door to the animal house, passing a rhino on the way and patting the giraffe inside, Sarah Forsyth points out small white boxes that dot the walls. "Everywhere you look there's a detector or a motion sensor," she says, chuckling in front of one that presented the security firm with a peculiarly zoo-specific problem. "These are the ones the giraffe were licking."

She can laugh about it now, but two months ago, when Colchester zoo decided to put in place the £300,000 alarm system, Forsyth's overriding emotions were panic and disbelief.