Close observation of the behaviour of fast-moving mustelids in the field is difficult over any useful length of time. The behaviour of stoats and ferrets adapted to captivity may not be entirely normal, but experimental testing of hypotheses can be done there provided the conditions are sympathetic to their nature. Neophobia (refusal to engage with strange devices) can cause learned aversion to field equipment. It also varies between individuals, so distorts the assumption of equal catchability. Captive stoats, used to a female carer, reacted with especially pronounced body rubbing and anal gland scent marking to the scent of human males introduced into their cage. Remote cameras normally use infra-red (IR) lighting, invisible to humans, for video surveillance. Ferrets trained to respond to a visual stimulus responded with 89% accuracy to a white light (LED); two of five continued to respond at 84% and 78% to a standard IR (870 nm) LED. One could not see a 929 nm LED. Competition within New Zealand’s predator guild is mitigated by the environment. Stoats confined to a pen are scared of a direct confrontation with caged cat, but in nature they can avoid each other via different activity schedules.