During a conversation recently, the topic moved on to Leaping Ledges. We thought the price was a little high for what they are. I thought about finding a volunteer to make a few up for the club shop, however, the reality is they are very straightforward to make.

I've been making wooden bits and bobs for our rats since we had our first two from Gill. The best has always been a length of smooth planed untreated wood from B&Q or similar. With a few bits of ironmongery, a little imagination and a little time you have perches and platforms, shelves, ledges and floors.

For those of you who have used the cage calculator, you'll know that bigger cages are better, but taller cages need shelves, ledges and hammocks to use all that space properly. And, of course, we all know how rats like to climb on to high lookout points (and go to sleep if they're bucks).

For simple shelves or ledges, all you need to do is measure cage from front to back and from side to side and write the measurements down on a piece of paper. Take a tape measure and a calculator and put a hand saw in the boot. Drive to B&Q or similar.

Find the smooth planed lengths of wood and see how long they are. Calculate how many cage lengths and cage widths you can get out of a length of wood. (A calculator and a trip to the coffee shop may help here!)

Now find the bolts and washers aisle. You will need to buy: four bolts (about 20mm to 30mm, M6), four repair washers and four T-nuts (M6) for each shelf you are going to make. (Repair washers also known as penny washers as they are roughly the size of old pennies.) Pick up your wood and head to the checkout.

An example of T-nuts

If you have a short car, you'll be glad you packed the saw. With this in mind, measure out one of your longer shelf lengths and add a little more (from what is going to be waste wood). Lean the wood over a trolley or railing and rough cut it. Once you have got it in your car and back home, you can cut it properly at your leisure.

Back at home, lay out your pieces and measure them up. As the shelves will go inside your rats' cage, remember to use inside measurements. Mark your wood clearly - if you make a mistake, it'll probably be because of this and not your use of saws and drills! If you have a square then use it. If you haven't, don't panic - it's not essential, but do use a ruler and take care to mark your lines at a right angle to the edge.

Now cut the wood into the required lengths. At this point you should have shelves but no way of attaching them to your cage. That's the ironmongery is for. (If you're not too confident, now's a good point to check the shelves do actually fit before moving on to the next bit.)

Pick up a T-nut and choose a drill that is the same size or slightly smaller than the tube on the T-nut. (Holding the shaft of the drill bit right next to the tube of the T-nut is an excellent way to check this.) Mark two points on the end of the wood then drill two holes about 1½" (40mm) deep. The T-nut should fit snugly in the hole - it is likely that you will need to persuade it in place with a hammer. (That said, if the hole is too small, you will see what looks like matchsticks sticking out from the middle of your T-nut - this will stop the bolt from fitting and will need to be removed.)

Putting the shelf together à la Haynes

Dip the end of the bolts into some cooking oil, put on a washer on each bolt and check the bolts fit into the shelf. Repeat this for each end of each shelf. Fit them in the cage and don't forget to sweep up.

I'm not going to claim the shelves last for ever, but eventually you may need to make some new ones. In this case, don't forget to salvage and re-use the ironmongery - it's where half of the cost is.

You can also experiment with other designs. Two simple ideas to get you started are corner shelves (if you can draw lines at 45°) or using a shelf or two perches threaded through a leg cut off a pair of old jeans to make a hammock.

Barbie modelling the finished product