Though unlikely to harm you, there are a few pests that you will want to avoid in NZ:
Sandflies – Very unpleasant little bloodsuckers, sandfly populations are densest around Fiordland and on some parts of the West Coast of the South Island. They are least active on bright, sunny days, in windy conditions, and at nighttime. Remember, they fly very slowly so you are safe if you keep walking!
Mosquitos – We can blame human action for introducing most of the mosquito species that attack humans in Aotearoa; native species evolved to feed on birds, seals, and bats. Luckily, these bloodsuckers do not transmit diseases here.
Wasps – Similarly, the most offensive stinging wasps were introduced to Aotearoa from Europe and will be immediately recognisable to many visitors. They are a significant problem in some forests in NZ, and you will see wasp traps on some tracks.
Spiders – The vast majority of NZ spider species are harmless to humans. There are venomous katipō, redback spiders, and the biting white-tail, but your chances of being bitten are incredibly low.