Clicking input field doesn't indicate that a new text can be input now

When you click on an input field nothing changes. The "Enter text here ..." text is still there. You can input the text but the user should see that this is the case. Normally if you click on an input field it either removes the "Enter text here..." text and shows a blinking cursor or it selects the current text. So how do I do that with the input field in Unity? And why isn't that the default behaviour in Unity?