<P> Male canines are the only animals that have a locking bulbus glandis or `` bulb '' , a spherical area of erectile tissue at the base of the penis . During copulation , and only after the male 's penis is fully inside the female 's vagina , the bulbus glandis becomes engorged with blood . In coyotes , when the female 's vagina subsequently contracts , the penis becomes locked inside the female . This is known as `` tying '' or `` knotting '' . While characteristic of mating in most canids , the copulatory tie has been reported to be absent or very brief ( less than one minute ) in the African wild dog , possibly due to the abundance of large predators in its environment . </P>
<P> Male canines are the only animals that have a locking bulbus glandis or `` bulb '' , a spherical area of erectile tissue at the base of the penis . During copulation , and only after the male 's penis is fully inside the female 's vagina , the bulbus glandis becomes engorged with blood . In coyotes , when the female 's vagina subsequently contracts , the penis becomes locked inside the female . This is known as `` tying '' or `` knotting '' . While characteristic of mating in most canids , the copulatory tie has been reported to be absent or very brief ( less than one minute ) in the African wild dog , possibly due to the abundance of large predators in its environment . </P>
where does a male dog enter a female dog
where does a male dog enter a female dog
vagina
vagina