There are a number of factors to consider:

To protect one spot, one snake repellent may be sufficient.

To protect the area immediately around your house, one repellent at each corner could be enough to provide overlapping vibration between adjacent repellents. The best coverage is when the snake repellents are away from the walls, say 5m.

Protecting the whole property is also practical by forming a barrier around your fence line. The repellents are placed no more than 25m apart.

If you have snakes coming from a certain direction, for example, neighbouring grassland, you could simply place the snake repellents along that boundary. The repellent action will transmit under most fences so in this way you keep the snakes off your property at a distance.

Some situations may require more repellents.

Soil types: The 25m apart is a maximum range for most soils, but for sandy soil or soil with a lot of fine stones, you should reduce this to 10m apart.

Hard objects: If you have pathways, you'll need a repellent on both sides because the vibration doesn't pass through hard objects in the ground. This applies to concrete, bitumen, gravel, pavers, etc.

Shallow topsoil: If your topsoil is shallow then reduce the separation between repellents.

Multi-level ground: You'll need snake repellents on both levels where the ground is terraced because the vibration won't travel between levels.

Soil cracks: If the soil is dry and cracked you'll need repellents on both sides because the vibration doesn't cross the gap.

Do Sureguard Snake Repellents repel lizards, eg. Blue Tongues, etc.?
No, they are designed for snakes and there is no evidence of lizards being affected.

Do Sureguard Snake Repellents repel frogs, toads, birds, pets, etc.?

No, they are only designed for snakes.

Can snakes be caught inside the protective boundary?

It is possible. If you already have snakes living in your garden, you should consider having them professionally removed before installing the repellents. (Try searching for: snake catcher, snake removal or snake handler). Another strategy is to install the repellent centrally, say around the house area, then week by week move them further away until you have them all moved to your property boundary.

Can snakes get used to the vibration so it becomes less effective?

Repeated exposure to the vibration could lessen the deterrent. In psychology, this is called desensitisation. In practice, this is rare because the snake moves out of the area. However, take care not to inadvertently trap the snake in the protected area. For example, one Sureguard customer had a snake under the slab of her house. She placed the repellent at the entrance of the hole to repel the snake. The snake did not come out for weeks, obviously feeling trapped, but eventually overcome its fear and went past the repellent. The correct installation would be to wait for the snake to exit the hole and later place the repellent there before the snake returned.

Do the repellents work on all snakes?

Sureguard Snake Repellents work on most snakes moving along the ground. A python moving off a tree onto your aviary won’t be deterred. Similarly, tree snakes won’t be affected. Juvenile snakes may respond poorly. Sureguard does not recommend using repellents against the species Acanthophis antarcticus (Common Death Adder). Unlike other snakes that tend to move away from human activity, the Death Adder's method of hunting by ambush means it tends to stay hidden. (Reference: Wikipedia - Acanthophis).

I saw a snake moving off in the direction of a repellent, why?

To explain this behaviour you need to understand the psychology of how the product works and a concept in psychology called the “fight or flight response” (see Wikipedia). When a snake is casually moving through the environment and starts to detect the vibration, it chooses not to go there. Perhaps it is dangerous, the snake does not know. Is there an urgency in the snake’s mind? Not necessarily. If the snake is casually moving toward the protected area the snake may simply change direction without you ever knowing it was around. However, when you saw the snake moving quickly it had likely already detected you and chose to quickly move away. This is a natural “flight response”. Did it also detect the repellent? Not necessarily so; the repellents emit a pulsed vibration every 30 to 60 seconds. Between the pulses, there is nothing to sense. This would explain the snake’s poor choice of direction.

I found a snake sunning itself on some garden steps. Why wasn’t it repelled?

Carefully analyse how the snake may have travelled to that point. Remember, the repellents won’t affect a snake moving on some hard surfaces, e.g. concrete, pavers, bitumen, etc. For example, Sureguard had a customer call our technical department for assistance. Repellents had been installed around the whole back yard but a snake later found its way to the back door. When we analysed the installation we found a 2m section of concrete pathway unprotected on the property boundary because it was not considered worthwhile placing a repellent on this narrow strip. It was effectively a hole in the boundary which the snake happened to come through then travel on the concrete to the back door. A repellent had been used on one side of the concrete pathway but the protection didn’t extend across to the other side. The solution was to place the repellent on the other side of the pathway. This solution worked.

I have a snake on my roof, can I place the repellent there?
Sureguard Snake Repellents have only been designed to repel snakes on the ground. Do not hang them on the roof or gutter, or on trees or other structures.