Do I need a virus scanner for my iPad?

No you dont need any anit virus software for the iPad or any other Apple iOS device. Apple iOS devices uses a technique called "Sand Boxing" for all their apps, in short terms any apps that you download can only interact within its own app parameters, hence the name "Sand Boxing" only letting that app play within its own sand box! Now some apps may require to have access to your contatcs or calender events for example "Facebook" is a good example but for that to happen you have to allow for this to happen, it will prompt you when you first open the app if you change your mind later that can be easily change in the privacy setting. Hope this answers your question!