Speaking of which, skills!
Basic Skills: Hide, Move Silently, Spot Hidden, Listen, Insight, Foraging, Grappling, Intimidation, Negotiation
Weapon Skills: Bite, Claw, Needle, Launching
Unique Skills: Web-weaving, Trap-making. Nest-making, etc.
Basic Skills all have a yet to be decided base rate, possibly based on their stats. Characters with abilities will get unique skills to match them. Characters get a weapon skill for each attack type they have. Characters then have 100 points to spend to improve all their skills above base rates.
Special abilities are all taken from the mutations section of BRP. Characters are assigned appropriate "mutations" as befits their species
Suitable Mutations include: Adaptability, Camouflage, Group Intelligence, Hardy, Keen Sense, Luminescence, Natural Armour, Pheremone, Regeneration, Sensitivity, Venom, Wings.
Attack damage would be based on a set damage for each attack type, say: d6 for a bite attack, modified by Damage Bonus, which is affected by Strength and Size.