It's nightfall at Chester and the zoo's 800 nocturnal inhabitants start to wake up. Aardvark Koos is showing a potentially romantic interest in his sister Himba, but the zoo needs to ensure that their animals are breeding from the right genetic pool. As daylight arrives the keepers try to coax Himba into a crate to take her to another zoo. But she's now half-asleep and proving to be a stubborn aardvark, so it's not easy. It's time for nocturnal mouse deer Una to leave her parents and meet a mate. The zoo have a new space for her and her future partner Biani but she's proving shy, and hides in her new nesting box day and night. Can the arrival of Biani persuade her to come out? It's the final lunar cycle of the seahorses' mating season. Seahorses are one of the few species where the male gives birth, and clumsy underdog Seabiscuit needs to attract a female in the next week so that he can incubate her eggs and give birth at the next full moon.