small animals

Pray

Extract of peppermint for spiders and coarse salt for snakes. Put under your Rv and replenish as needed.

Use spray foam and wire mesh/steel wool to fill any holes allowing creature access into your RV.

As indicated by gbopp, best practice is to prevent entry. Then, as backup, place a BUNCH of glue traps all over, which, unlike poisons, will allow easy retreaval and disposal of anything that gets through your perimeter defense. If possible a few solar lights outside at the edges seem to deter pack rat activity which may save wiring looms.

I lived in Tucson in the last 60's. We made a trail of baking soda and boric acid powder across and behind all our cabinets. We always put our socks in our shoes when we went to bed. We always flipped the covers down before pulling the covers up. And we still had bugs.