It's a good thing the Stalkers are taking a liking to Dave in return (or is that a bad thing?) because they'll be happy to follow him when he wants, continuing to bring him and Rose metals in exchange for treats. A few bonus items will include a first aid kit in perfect condition, a bag of fruit flavored gummi treats and some sort of shiny metal goat toy that bleats when squeezed (which will startle the poor Stalker).

Humming the song will distract a Stalker. It appears to calm it and it will wait after the song has finished, though what it's waiting for is unknown and even it will seem confused when it snaps out of it. One of the Stalkers may be a little affectionate after hearing the song and bump its nose against one of their heads.

The mapping will go very well and they'll even find some deeper levels of the cave, where they'll discover a gray, lumpy egg in the midst of hatching. What pops out? Well, it's some sort of fish at least. And it'll quickly bond to Rose and Dave, chirping and clicking at them and swimming (awkwardly, since it is a newborn) around them. It will try to hide from Stalkers and Stalkers will have an interest in it as food, so if they choose to take their new baby home, they'll have to be careful.

If you have any questions or need further clarification, just ask!