Unfortunately, few, if any, of the dealers who sell monitor lizards also sell enclosures large
enough to keep them in! For this reason it is necessary to employ the services of a builder or
carpenter, or construct the terrarium oneself. The important qualities of the enclosure are
that it be easy to keep clean, well ventilated, strong enough to withstand repeated attempts to
escape and have good heat retaining properties. Enclosures for aquatic monitors must also be
waterproof. A variety of materials are suitable, just a few of which are described below.
Members of your local herpetological society will doubtless be able to suggest many more.
Ideally all terrariums will have some sort of drain on the floor that facilitates cleaning and
prevents the substrate getting waterlogged. A false bottom in part of the enclosure can also
be useful. The enclosure must be well ventilated and provision for fans and vents should be
made during construction.
The simplest and best enclosure for large monitor lizards is an unused room, ideally a cellar.
Attics suffer from massive temperature changes and can become incredibly hot on a summer
afternoon and very cold at night. Very careful attention to heating and ventilation is required
in such enclosures. Large monitor lizards can tear plasterboard walls apart like wet cardboard
and it is usually easier to build a large enclosure rather than allowing them the run of the
room. Brick and concrete are often used to make homes for the giant monitors. Their main
disadvantage is that once built they are difficult to dismantle, but given the great ages
reached by varanids it should be many years before this becomes a problem. The benefits of
these materials are recognised by everyone who lives in them; to all intents and purposes they
last for ever, are immensely strong, retain heat well and can be built to any size and shape
Glass is expensive and normally is used only for the front of the enclosure. The price of glass
of the size and strength needed to contain most varanids would make the cost of an all glass
terrarium astronomical. Second hand window frames (with or without glass) are ideal for
incorporation into larger enclosures and can often be obtained very cheaply. Frames with
cracked panes are useless unless the glass can be replaced entirely. Large monitor lizards
have been known to smash through extremely expensive armoured glass. Aquariums make
good homes for hatchlings and for dwarf lizards. Their main disadvantage is that they tend to
be very narrow and tanks over 50cm wide usually have to be made to order. Large aquariums
make ideal enclosures for smaller amphibious monitors such as V.mertensi
. especially when
additional "dry land" is also provided. Hatchling monitor lizards grow at such a phenomenal
rate that they must be moved from the aquarium into more spacious quarters after a very
There are some excellent fibreglass and plastic terrariums on the market. which are made
especially for reptiles. but they are not available in sizes suitable for most monitor lizards.
Factories may be able to supply large moulded tanks which can be adapted to make suitable
enclosures but they are likely to be expensive. Look under "glass fibre" and "plastic" in the
yellow pages and enquire about imperfect products. which may be available at much lower
prices. Alternatively cement and plaster can be used to build the walls of the enclosure and
the inside can be coated with a mixture of sand and epoxy resin, making a very strong,
waterproof finish that is aesthetically pleasing.
Wood is widely available and relatively cheap. It can be used to make enclosures of virtually
any size or shape. The usual choice is a simple wooden box which can be knocked together
by almost anybody. Laminated chipboard
(particleboard) is one of the best materials for small
and medium sized monitors: it is relatively inexpensive. easy to keep clean. is available in
large sizes makes a strong terrarium if constructed correctly and can be made waterproof
with a few coats of liquid rubber or polyurethane varnish. The construction of a very simple
chipboard enclosure is outlined in Appendix V but the best source of information is the local
Herpetological Society. Reptile keepers are often ingenious in their approach to building
terraria and are always happy to pass on advice.
When a monitor lizard is free from disease it is possible to keep it that way by keeping its
enclosure and furnishings scrupulously clean. This means periodically (every few months)
taking the enclosure apart and disinfecting it. Therefore the furnishings used should be either
easy to clean or cheap to replace.