In one scene, some of the Pikachu chew on the rope bag (whatever it's called) that is keeping them captive. This is in line with behaviors that their real-life counterparts, mice, exhibit (though mice usually chew on wires - electric ones at that).
So yeah, Pikachu and its relatives should learn Bite and similar attacks.
This user supports Brock/Ash and Cilan/Ash
Ceci n'est pas une signature
I walk through the valley of the shadow of death
Shippings I support: Ash/Misty, Drew/May, Kenny/Dawn, Ash's Pikachu/Dawn's Buneary, Tracey/Daisy, Cilan/Iris, Clemont/Serena, Harley/Zoey, James/Jessie, Max/Bonnie, Max/Mira, Max/Vivi Winstrate (I multiship Max and only Max), Butch/Cassidy, Gary/Lillie, Kiawe/Lana, Sophocles/Mallow, Lunick/Solana, Wes/Rui, Brendan/Game May
RIP Blake Carrington, Ben Matlock, Joe Mannix, JR Ewing, Jim Phelps