Related Clues:

• Alert people are on theirs
• What ballerinas often dance on
• Big digits
• Paw parts
• Nail sites
• Podiatry subject
• Drives obliquely
• Tips of shoes
• Foot attachments
• Tot's 'piggies'
• __ the line
• Aids for counting to 20
• Piggies of verse
• On one's ___ (alert)
• Low digits?