Hector Duarte Jr. - All Headline News Staff Reporter

Study leader Stephen Rossiter of the Queen Mary, University of London, says the females will not mate with their fathers, but will mate with their mother's partner, only when the mother has switched partners.

Rossiter suggests this strange behavior evolved to tighten relationships within the colony.

In some cases, a female and her maternal half-aunt were also half-sisters on their father's side. While confusing, the best way to break it down would be as follows: Female 1 mates with male 1, producing female 2. Later on, female 1 ditches male 1 and mates with male 2, producing female 3. Meanwhile, female 2 gets in on the action and also mates with male 2. Female 2 now jumps in, mating with male 2, producing female 3a.

Females 3 and 3a are related in two ways now - female 3 is 3a's half aunt on their maternal side, but they're sisters on their dad's side.

Since horseshoe bats have a life span of about 30 years, this loopy family tree gets more and more complicated down the road.

This study was part of one of the world's longest-running wild animal population studies. The research is detailed in the Sept. 15 issue of the journal Nature