In Richard Scarry's Best ABC Video Ever, they appear in the letter F segment (fire engine), and the mouse firefighter also appears in the F (fire engine) and U (uniform) segments.
In Richard Scarry's Best Busy People Video Ever, they appear in the firefighter segment. So does the mouse firefighter.
In Richard Scarry's Best Silly Stories and Songs Video Ever, they try to get Mr. Rabbit unstuck with a hose in the first story (Absent-Minded Mr. Rabbit), are confused that their fire engine's siren Mr. Fixit fixes says "mama" like Lily Bunny's doll in the second story (Mr. Fixit Fixes It) and are waving at Pa, Harry and Sally Pig with the new car in the third story (Pa Pig's New Car). The two mouse firefighters also appear in the second story and they laughed after the siren says "mama". They appear in all three stories.
Squirty and Chief don't appear in Richard Scarry's Best Videos Ever.
Fireman Ralph and the mouse firefighters don't appear in The Busy World of Richard Scarry and Busytown Mysteries.
Chief doesn't appear in Busytown Mysteries.