Puerto Rico, Guam, the US Virgin Islands and the Northern Mariana Islands.
Territories do not have US Senate Representation or a voting member in the US House.
It already does. That's how the membership of the House of Representatives is determined.
Population.
They do not have the same House of Representatives members because the amount of members is based on population and not all US states and territories have the same population.
The house of Representatives. There are 435 total. The senate has two representatives from each state.
Amendment XIV
Each state is entitled to one of the 435 representatives in the US House of Representatives, regardless of the state's population. The other 385 representatives are apportioned according to each's state's population as a percentage of the total US population, determined by the most recent census. This is known as "proportional representation."
The house of representatives ~ APEX
There are 15 Michigan Representatives in the US House of Representatives. There are 110 Representatives in the Michigan House of Representatives.
In the United States, representation in the House is based on population, as determined by the Census. Which is what makes the Census such a big deal; with a fixed number of representatives, if one state loses population while another gains, that state may lose a representative to the other state!
Idaho has two US Senators and two US Representatives in Congress.
There are 435 voting members of the US House representing the 50 US states. There are even more non voting representatives that represent US territories and Washington DC. Non voting representatives can only vote in committees.