A Connecticut zoo is welcoming a new baby anteater, but the birth is a bit of a mystery. The male anteater was removed from the space in August, leaving the female anteater no mate and the conception a bit of a miracle.

The anteater’s conception at LEO Zoological Conservation Center, in Greenwich, Conn., has puzzled zookeepers. The only single male anteater within the enclosure was removed last year and an anteater’s gestation period is six months, meaning the baby anteater, named Archie, would have been conceived sometime in November, well after the removal of Alf, the male anteater.

Alf shared the space with a female giant anteater named Armani, who gave birth to Alice in August, notes the Greenwich Times. Alf was removed from the space as a preventative measure as zookeepers feared he might kill baby Alice. When one of the handlers went into the space to care for Armani in April, the zookeeper discovered she had given birth to a male anteater.

According to Greenwich Times, there was simply not enough time from when Alf was reintroduced to the enclosure to allow for conception, making Archie a bit of a mystery. Marcella Leone, founder and director of the LEO Zoological Conservation Center, believes there may be an explanation for Archie’s appearance.

Leone thinks Archie was conceived through delayed implantation, when the embryo does not immediately implant into the uterus. Instead, the egg remains dormant until the time is right, be it favorable environmental conditions or other health concerns. Some animals known to undergo delayed implantation include armadillos, bears, badgers and kangaroos.

Leone notes giant anteaters belong to the same mammal group as armadillos, making delayed implantation a possible but unlikely cause of Archie’s conception, notes the Greenwich Times. Leone is stumped as previous research indicates the probability of delayed implantation is rather slim. If Alf fertilized eggs during the time he was allowed to mate with Armani, prior to the birth of Alice, the pregnancy would have cleared out any fertilized eggs from the female giant anteater’s uterus. Stacey Belhumeur, a zookeeper and anteater survival plan coordinator, told the Greenwich Times, “Anything that's in her uterus, even another undeveloped embryo, would clear out.”

The birth of Archie remains a happy mystery, and Leone suspects that somehow Alf and Armani managed to mate after he was removed from the enclosure.