26/04/2012 13:36 BST | Updated 26/04/2012 14:01 BST

Why Being A Faithful Partner Is A Matter Of Life Or Death For A Spider...

It's a hard life being a male spider. Sex destroys your genitalia and then your partner will - most likely - eat you.

But, for those spiders who make it back to have another go (spiders are given two 'palps' with which to mate), half will remain monogamous and head back to the lady spider who made their first encounter so memorable, says new research published in BioMed Central's open access journal Frontiers In Zoology.

So far, so unlike humans.

But wait. In another twist of 'spiders aren't like humans' logic, the male is more likely to head back to the woman if she is... on the larger size (as bigger females tend to be more fertile).

Klaas Welke explains to Science Daily: "Amongst spiders, regardless of age, heavier females are the most fertile. Males were more likely to mate twice with the same female if... she was heavy."

In addition, the male spiders who preferred not to remain faithful preferred to 'trade up' to heavier females as second mates, says the report.

However, this is a risky mating strategy as there's a good chance another male spider will have already left their 'palp' inside that female, thereby forming a 'plug' to prevent such antics, researchers point out.

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