Elec Spiders are Vermin not Animal, you still hit it. Not only that, you also rolled a critical hit, which then needs to be confirmed with a second attack roll that if it also beats the AC then you deal extra damage. This roll is your critical hit confirmation roll:
1d20+1

Hilda , during your watch you see something stalking around the tree-tops near the camp. It moves in the branches slowly. You've ample notice to call out an alarm and very quickly the party it ready and armed, even Landowe, though he looks very panicked. Stepping slowly out of the moonlight shadows...

Rolling for Hilda:
1d1001d1001d20+31d20+3

Kull , you manage to catch a couple of rabbits fairly quickly. There's enough old driftwood on the side of the river that's dry enough to burn so it doesn't take long to collect enough for the night. Arlette as far as you're able to determine, there's been no one in this camp recently. Elec it seem...

Arlette you are safely back across, a little bit richer. Landowe slaps his knee laughing, it seems he's quite enjoying himself. "Let's get a move on!" he calls. "No sense in more delays!" The rest of the day goes without further incidence. About an hour after lunch, which was eaten on the move, you...

Arlette you once again lose your balance but manage to prevent yourself from falling in. Roll another Balance Check, if you roll a 7 or less you fall in and we'll see if your reflex save helps you. If you roll a 12 or higher, you make it across, an 8-11 and you can roll it again.

Arlette you very nearly lose your balance but manage to regain it at the last moment. Make a second Balance Check to continue the rest of the way (no need for a second swim check, we'll use the first one. Make a Reflex Saving Throw as well in case you fall in (that swim check result isn't great).

Landowe brings the wagon to a halt on the other side of the bridge and watches, waiting and smiling while Elec ties the rope to the wagon and Arlette wraps it around her waist. Arlette has no problem walking across the log and lands safely on the island. Up close she sees that a ragged old cloth has...

"Alright! Let's get move on," declared Landowe as the halflings melted back into the forest. The morning fog lifted fairly quickly once the sun had started to rise and within an hour it was almost entirely gone. Now that the wagon is out of the forest, the surroundings are bare and rocky hills, inte...

Arlette you don't pick up anything untoward from either of the Halflings. The one who greeted you is named Sheelmel and the one trading with Landowe is named Reenreen. They seem unwilling to discuss where they are going or where they come from, though this seems more caution from them than any act ...