In Apis spp (Honeybees), male genitals explode or snap off inside females after mating. The snapped-off penis acts as a genital plug to prevent other drones from fertilising the queen.

In pileworm, male and female bodies explode during mating period to release sperms and eggs, respectively. This obliterates the searching for a specific mate.

In alpine salamander, gestation period lasts up to 38 months (1140 days). It has the longest gestation period.

To test sexual readiness of a female, a male giraffe tastes female urine. This process is referred to as fleshmen sequence. Once the estrus is determined, male begin to court female.

Neck length is the criterion for selection of mate in galapagos giant tortoises. The male with the longest neck mates vehemently with female for hours with a lot of grunts and roars.

In Carcharias taurus (sand tiger shark), young ones eat each other within the womb until only two are left in each uterus. This is done to limit competition for resources.

Correct Answer: Young ones grow inside mother's body and eat her from inside as they grow.

Retractable and prehensile penis is a characteristic of dolphins. A male dolphin can use its penis to explore objects, just like a hand.

Correct Answer: calcium carbonate, chitin or cartilage

Pseudopenis is found in spotted hyena. To mate, the meeker male has to insert his penis into her pseudopenis. Females also give birth through pseudopenis.

In Percula clownfish, male turns into female if the breeding female dies. This guarantees that breeding female is always available.

Frigatebird males have inflatable red-coloured throat pouches called gular pouches, which they inflate to attract females during the mating season.

Traumatic insemination is seen in Cimex lectularius (bed bug). The male stabs female with knife like penis and injects sperm directly into her bloodstream.

Argentine lake duck is accredited with the longest penis of any bird species in the world. The male Argentine lake duck has a 42.5 cm long penis.

Female polar bear, after pregnancy, does not eat, defecate or urinate for months to maximise resources for young cubs.