The main topic of the talk was the mimicry complex of phasmids mimicking leaves and twigs, their eggs mimicking seeds, the eggs being taken into ants nests to protect them from parasitic wasps that may mimic ants, and the hatchling phasmid nymphs mimicking ants.
We know very little about this system (even less than we know of the ecology of the stick insects and wasps), but I am keen to find out. (More about this later).
After the talk there was a question session which addressed some further points about mimicry, the danger of studying species in isolation from the species they interact with, and a bit about cockroaches (with some help from David Nicholson who I am doing some Nature Live talks with in May).
There are some more photographs of the event on my Flickr set Cafe Scientifique.