AngularJS ng-repeat over json query

Im using AngularJS in a project. In my view I repeat over some employees and show them on the screen. That works, but I have to use the code

<li ng-repeat="employee in employees.employee">

instead of

<li ng-repeat="employee in employees">

Why cant I directly access the employees to loop over the different json objects?

My code snippets of the project:

Controller

Test.controller('EmployeeListController', function($scope, Employee) {
    $scope.employees = Employee.query();
});

HTML View

<ul>
    <li ng-repeat="employee in employees.employee">
        <a href="mailto:{{employee.email}}" title="{{employee.email}}">{{employee.firstName}} {{employee.lastName}} ({{employee.email}})</a>
    </li>
</ul>

Factory

Test.factory('Employee', function ($resource) {
    return $resource('/TestServer/rest/employees/:employeeId', {}, {
        update: {method:'PUT'},
        query: {method:'GET', isArray:false}
    });
});

JSON Response

{"employee":[{"created":null,"description":"TestDescription","email":"TestMail","firstName":"TestFirstName","id":"1","image":"TestImage.jpg","lastModification":null,"lastName":"TestLastName","phone":"121212121212"},{"created":null,"description":"TestDescription","email":"TestEmail","firstName":"TestFirstName","id":"2","image":"TestImage2.jpg","lastModification":null,"lastName":"TestLastName","phone":"2124343434"}]}