Males are simultaneously polygynous, females are serially polyandrous. As such, polygamous relationships can be polygynous, polyandrous or polygynandrous. Most mammals are polygynous, but some can be monogamous or polyandrous. The mating systems within the genus "Ursus" are primarily classified as polygynous, polyandrous and promiscuous. Often, cryptic female choice occurs in polyandrous or polygamous species. For this reason many considered Spartan women polygamous or polyandrous. Although polygyny is more common, some tribal societies are traditionally polyandrous. Polyamorous and polyandrous marriages are, likewise, still prohibited. However, both monogamous and polyandrous groups are found in south Sumatra. Female red flour beetles are polyandrous in mating behavior. "Vespula germanica" queens are typically polyandrous. He believes that both polyandrous "sambandhams" and hypergamy were most common in Central Kerala. Intrauterine insemination causes an evolutionary consequence resulting from polyandrous behavior. This indicates some taxa of anglerfish use a polyandrous mating system. This indicates the anglerfish use a polyandrous mating system.