I don't know about pest in Ubud, but we once stayed in a very nice Maya Ubud resort, stayed in a one bedroom villa, with plunge pool and all; just one thing; little critters. Since it's a villa, sitting next to gardens, rice paddies field and all, so small insects like big ants, little lizards does come into the villa. Which is why they equipped the room with bug sprays as well. So if you're not into those, may want to stay in a multi-story hotel building.