In Episode 8, the party encounters giant rats, but it could have been one of several other discoveries/monsters. Here's the table I used.
1 Evidence of Raphinfel’s passage
2 5-9 Giant Rats
3 3-6 Kobolds
4 3-6 Giant Spiders
5 2 Sprites
6 5-9 Giant Centipedes
7 3-6 wolves
8 3-6 stirges
9 1-4 Gnolls
10 Abandoned Hut – small chance of treasure inside
In a very early episode, I complained that the wandering monster tables in Basic D&D made no sense. I now realize that they are for dungeon crawls only and that the Expert rules contains the outdoor encounter frequency chances. Not really well organized, is it? My ruling was to make one check a day. Expert rules stipulates one per day and one per night, so I got it wrong, but ... it's no biggie. Rulings, not rules, right? That's the OSR way. I might switch to the official ruling or keep my own in the future - time will tell.