To simplify the expression \( m^{-4} \cdot m^9 \), you can use the property of exponents that states \( a^m \cdot a^n = a^{m+n} \).
Applying this property to the given expression:
\[ m^{-4} \cdot m^9 = m^{-4 + 9} = m^{5} \]
So, the simplified expression in exponential form is:
\[ m^{5} \]