Hi Shee,

The problem you are asking is for multiclass classification of images.

For binary classification we use sigmoid activation function

classifier.add(Dense(units=1, activation='sigmoid'))

For multiclass classification, as in your example where we need to classify dataset of 5 animals, we will use Softmax activation function.

The above code would now change to

classifier.add(Dense(units=5, activation='softmax'))

Hope this helps