When stressed, these male spiders woo mates with empty 'take-out containers' instead of dinner

Certain male spiders in South America usually give their partners a tasty snack before mating. But in stressful environmental conditions, males may "cheat" in their mating ritual by offering females a useless ball of silk instead of a nutritious meal, a new study has found.

The research shows how spiders may adapt their behavior to reflect changes in their environment.

When a male Paratrechalea ornata spider wants to mate, he'll snag an insect and prepare it for a female, said study co-author Maria Albo, a biologist at the University of the Republic in Uruguay.

Related: Female spiders play dead during sex so males don't have to worry about being eaten

The spider starts by wrapping the insect in silk over and over until it forms a nice, little ball with a juicy treat hidden inside. "And then they start to walk along the river, along the stones," Albo told Live Science.

If a female takes the bait, she'll grab onto the gift with her mouth and slowly digest the silk to reach the food inside. While that's happening, the male mounts the female and they mate.

But some P. ornata males try to mate without going through the hassle of giving a gift. Instead of packaging a piece of food, these males will wrap up something not so tasty, like a leaf or even the leftover bits of an insect they've already eaten.