Kids have an incredible knack of testing your limits.

It doesn't matter how old they are they will see how far they can push your boundaries and test the rules you set for them.

Sophie, mum of two young boys, 5 and 3 years, says they love to ask her for treats, even if they know that they're not allowed to have them. "If it's a weekday I stick to my guns and I say, 'no', but if it's the weekend they know they can get a treat so they keep asking until I give-in."

Sophie's story is fairly typical of many parent-child relationships.

Whether children are asking for a new toy, to stay up late, read another story, or take a prized possession to school, when they continually ask despite being told, "no" it becomes exhausting. Often as parents we give-in.

So why do children keep asking their parents for something when their request has been denied?

Dr Erica Reischer, psychologist and parenting coach explains: "Our children are always experimenting to find out what works to get what they want… how parents respond in these situations can inadvertently teach kids to keep pushing limits. The key is consistency," she said.

She explains that by being consistent your children learn that you mean what you say and they will stop testing your boundaries. Conversely she says that inconsistency, "motivates kids to keep trying until they get the response they want."

She outlines three reasons why you might struggle with being consistent with your kids:

1. Parents aren’t paying attention to the situation. They don’t notice they are being inconsistent

2. Parents don’t want to follow through. Being consistent is inconvenient or uncomfortable for them.

3. Parents can’t follow through. Following through is not within their control.

An example of the second reason might be a daughter fighting with her sibling. Her mother then says out of frustration, "Stop fighting or I'm cancelling your birthday party." The child then cheekily continues to poke and tease her sibling.

In this scenario the mother is then in a situation of having to choose whether she should cancel her daughter's birthday party, which she would feel awful doing. Instead she could have chosen a consequence for her daughter that knew she could follow through with.

Dr Reischer says that if you want you child to accept your "no" as an answer without pestering, you need to enforce the rules that you set. "Be certain that you can and will enforce your rules and follow-through consistently on what you say you will do."