yeah so here's what I have on it so far:
they can find drill items, but they don't actually drill. So no lone pets wandering fields, and no feeding it drills to use.
you can use any pet with 3 stars or more;
3 stars: holds 100 items, 70% chance to find an item per "food item"
4 stars: holds 200 items, 80% chance to find an item per "food item"
5 stars: holds 300 items, 90% chance to find an item per "food item"
items do not stack it pet inventories meaning 2 spicy eggs take up 2 spaces.
the area in which you can have your pet "drill" depends upon it's level
1 - cora beach, desert beach, megalopolis
40 - caballa relics
60 - oops wharf(phantom school is seen as part of oops), mermaid palace, mirage island
90 - ghost blue, rose garden
120 - swamp
150 - snow hill, megalopolis underground
180 - techichi, altheo empire
210 - tapasco
270 - abyss
the levels are the minimum to pet drill there; a level 270 pet can drill anywhere, a level 250 pet can drill anywhere BUT abyss.
pet food items are sold in myshop in groups of 1,000. don't know the difference between the soda and chocolate bar. They speak like these food items or an ev version of them will become a very common event item, of course event rewards are version based.
(personal note; this is my personal view, not what it actually says: they should change the chance of finding an item to food item based, and have an in game food item with a low chance of finding an item, like say 30%)
the rest is how to set-up a pet to "drill":
you go to the region you wish for the pet to "drill" in.
you open the pet collection menu from the right click ring.
you select a pet from your inventory, load it with food, and set it's item pick-up rules (still reading those), then press the "play" button.
when done press the recall button and the pet will return to your inventory with all the stuff it collected.(you might be able to "drop it" before the pet brings it back to you)
this is what I know as of now. it does seems really myshop based, which is sad.