According to number of woodlice initially introduced, the dynamics of the dispersion of groups held for 300 s (a) and the time necessary to disperse 50% of the population introduced (half-life time) (b).

2015-06-11T03:00:41Z (GMT) by Pierre Broly Jean-Louis Deneubourg

For the experiment with 120 woodlice, only the first 1500 s were represented in Fig 1a for better visibility, but some aggregates persisted for more than 4300 s with 120 individuals.