How do I keep my cat inside?

We have had our male cat for over a year know. He started out an inside cat only, but through time he has learned to dart out of the door when he gets the chance, this started because we let him out. Well, after catching Poison Ivy from him (he sleeps on my pillow) We have decided to keep him an inside cat... How do we train him to stop darting out the doors? He is two and is neutered.

I think your best bet is to do the following:
(Possibly do this one, it may not be necessary) Put a scent outside that cats dislike, such as a mix of ground black pepper and chili, peels of citrus such as oranges and lemons, or pine cones.
Source: nana.asn.au/n2-catout.htm
On days your going to open the door a lot and hes more likely to get out, if you CAN get outside, try an spray water on the ground.
Scold the cat if he goes outside. Not in a harsh way, just get the message across that it's not okay.
Give him something to want to stay inside. A good scent for example.

Hope this helps/

This may or may not work for you, but every time my cat does something I want her to stop, I lock her up in the bathroom for a bit. I know the idea of giving the cat a time out seems really silly, but it works... it's slow, but if you're consistent he'll catch on, outside without permission=being locked up. Also scolding the cat is quite effective. Or try the spray bottle thing (I personally dont like it, but...))

Neutering him, if he isn't...will also make him more of a homebody...

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