The animals in this study are not subject to ethical standard laws
in the country in which these experiments were performed.
Moreover, there is little research into the humane treatment and
euthanasia of insects (Gunkel & Lewbart, 2007). None the less,
distress to the animals was minimized as much as possible:
although colonies were deprived of food for 4 days prior to testing,
this is well within what such colonies can tolerate before starvation
begins. Ants from which CHCs were extracted were chilled
at 20 C for 10 min before extraction, to minimize their distress.
Marked ants to be discarded were frozen at 20 C.