Night Spider - Australian Huntsman spider
Water Terrain - Fishing/Water Spider
Shed - Black house & Redback spiders
Slugs and Snails
Butterflies/Moths
Hard Mode Insects - Scorpion, Sydney Funnel Web, Fire Ants, Fish in water, Mosquitoes, Centipedes
I am not sure how the devs want to do this, however maybe in just hard mode or in all modes have some insects be able to climbs things. e.g. spiders should be able to climb branches on the Oak Tree with no issues. There would be other insects that would be able to climb other environmental objects as well. This would provide a harder mode or more cautious play for people when locating bases and moving around.
Also having spiders drop down from webs would be cool