While trout will feed on whatever is available to them at the time, there are certain food sources that played a much larger role in their diet. What they are feeding on will vary from location to location, over the year and even over the course of a day. Some of the made food sources are listed below.

Insects

In most rivers and lesser extent and still waters, insects at various stages of their maturity form the staple of the trout 's diet. The two major insect groups throughout the country are mayflies and caddis (sedges). Other important insects include stoneflies,  dobsonflies(  creepers), beetles, midges, lacewings, cicadas, crane flies (also known as daddy long legs) and snails. At times opportunistic trout will also feed on such as insects as blow Flies, wasps, dragonflies, bees and moths. By far the largest proportion of the trout's diet is taken when insects are in their larval a pupa stages. Much of the time they will be feeding on the stream bed.

Small fish

In lakes and on the larger rivers particularly around the river mouths, small fish also make up a substantial part of the trout 's diet. These fish include smelt, bullies and whitebait though trout will also eat juveniles from their own species. When the whitebait move into the rivers during autumn and early summer, the trout will often move downstream to take advantage of this food source. In the lakes where there are large smelt populations, trout will migrate in search of these small fish as they form the principal part of their diet.

Other food

Trout can be very selective in what they eat but will also take advantage of any food source that is offered to them. At times trout have been caught with tadpoles, frogs and even small mice within their stomachs showing that they are partial to variety in their diet. One particular food source that has been recognized by many anglers is of course fish roe or the fish eggs laid by spawning trout. Trout do not seem to be able to resist eating these when they are washed down stream in the current and these have been imitated successfully by Glo-bugs and Muppets.