  Ihara's proof that the reduction of the modular curve $X_0(n)$ at a prime $p$
not dividing $n$ has many points over a quadratic extension is adapted to the
drinfeld modular curves $X_0(n)$. In order to do so, some properties of
drinfeld modular varieties that have no proof in the literature are proven. The
text is more or less self-contained.
