See the tips¬es here: https://www.duolingo.com/skill/he/Verbs%3A-Present1
Whatever the gender is, in most cases you always say "duck". The word drake is not used commonly. It is used only when you really wamt to specify that you speak about a male duck. But even then, in 99% cases, people would rather say "male duck" and not "drake". In this sentence, the gender plays no role, so the default "duck" would be the first choice for virtually everyone.