Two teenagers have been charged over the deaths of two alpacas at a school farm north of Brisbane last year.

The male teens, aged 16 and 19, are accused of luring two alpacas from their enclosure at Caboolture State High School and then beating them savagely with iron bars about 5am on October 13.

Alpacas Harrison (left) and Harley were beaten to death.

The pair allegedly moved horses that shared the enclosure with the alpacas from the pen, but did not hurt them.

The male alpacas Harley and Harrison died after the attack. One died instantly, while the other had to be euthanised.