enclosure joining advice

[Pilchy]

hi all again
im going to make a new enclosure, theres absolutaly no rush in making it, its going to be a 2 tier
at about 4ftx2ftx2ft x2 its going to hold an adult coastal and a jungle, the coastal i have now is only 9 months old and roughly about 70cm long so really no rush and i will purchase the jungle abit after i have finished making it

but anyway here are the final plans

im just not sure how i should join these parts

should i drill out holes and screw it
is there any other easyer/ more effective way of joining it, i was thinking some form of runners that i could glue the piece into
i dont own a router so i couldnt make grooves in the board

also its going to be made out of mdf melimine board 16mm thick

 

[MrBredli]

If you're talking about the middle panel i.e. the roof of the bottom cage/the floor of the top cage, then screws through the side panels are all you require.