Twins are children born on the same day sharing the same mother.

It occurs after a fertilized egg divides into two separate eggs in early pregnancy or when two different eggs of a woman are fertilized by two different sperms.

Many people believes obviously that twin children always share the same father thinking that a woman can get pregnant only once in one stand after sleeping with a man but this may be totally different biologically according to research.

In a rare occasion, we can come across twins who totally differ from each other, not looking alike despite many believing that children born with the same mother in the same days always match due to identical DNA.

However, the twins might have different fathers in a rare occasion only if a mother sleeps with two different men within a day or after ovulation for both eggs to be fertilized.

It is hard to calculate the exact odd of the phenomenon, but previous studies suggested the chance could be between one in 400 pairs and one in 13,000 pairs according to the UK based ‘the Guardian’ publication.

Such occasion had happened different times; In China, a father discovered that one of his twin babies had double eyelids while the other had single like the one of himself and his wife.

In new Jersey, a mother of twins underwent paternity testing when applying for public assistance.

After the test showed that her partner was only the father of one child and she admitted that she slept with another man within three days after the first one.

Similarly, a mother of twins in Texas acknowledged that she had an affair with another man when paternity test revealed that only one of her twins boys matched with the fiancee.