Several wild species in the family also act as hosts, especially early in the season when cultivated crops are unavailable.

The researchers found that the two species acted somewhat differently in response to hypoxia.

The two species may act aggressively toward one another even when there is no food involved.

They had made no aggressive moves whatsoever, and, as always when people or species acted out of character, that made her suspicious.

These species also act to provide a source of protons to facilitate the ionisation process.

In some cases a single species may act as both the definitive and intermediate host.

The three species do not act aggressively toward each other.

Both species were acting to save their planet-bound fellows.

You must always trust a species to act in ways rational to its own culture.

In this account, it has been assumed that one species acts as a mimic and the other as a model.