Strength in numbers? Not always

We propose a simple model to compute the probability of success under a particular quorum sensing strategy. We show that this quorum sensing strategy has a higher probability of success than an individualistic strategy when, for instance, the probability of success for a single individual is low and the cost of building a quorum is not too high. On the other hand, if the cost of building a quorum is too high, then the probability of success under quorum sensing always decreases as a function of the quorum. We also give an example showing that the probability of success as a function of the quorum is not necessarily monotone. ► We propose a model to compute the probability of success under quorum sensing. ► Whether quorum sensing is successful depends on individual success probability. ► Quorum sensing success also depends on the cost of building a quorum. ► Quorum success probability is not necessarily a monotone function of quorum.