After Ran went out to search for Chen, Meiling went into the nest hole where they were living. There is one reason for Meiling not bring the two predators to kill Chen. That reason isn't to kill and eat the rest of kids there. The objective was to copulate with them and increase the war force.
One Chen has been crushed while trying to run away but the result of this plan was great. Without regret the Chen and Ran types were culled and used to recover the energy from the predators to let them refresh more. Also with this they would be fine when the parent-Ran came back.
They also culled the Flan and Remilia types that weren't friendly with both Predators. The number of Flans and Remilias that they got there are enough to their reinforcements. After they being born, Meiling and her friends left that nest.