As a warning, Bill, Misty knows where you live, so I wouldn’t dare make a comment about her or her fear of bug-types here. —LH
I wasn’t even thinking of it. Misty seems more like a dog person to me than a cat person. Although now that you mention it, she did have that togepi once, so… —Bill
Again, Bill. She knows where you live. —LH
To put it in short, anonymous, purrloin are very much like cats, and they have all the same instincts as our feline friends. This includes seeing us, their humans, as essentially giant hairless kittens. The act of bringing a human any sort of small, weak pokémon, including bug-types, is really an attempt to teach that human how to hunt.
That having been said, there are a couple of ways you can discourage this behavior. The first is by keeping your purrloin indoors at all times. This may be the trickier route, as many purrloin are clever enough to figure out ways to escape anyway, but if you supply yours with an incentive not to (in the form of new toys, particularly puzzle-like ones—some of which can be filled with treats or pokénip), he may simply decide to agree with you.
The other option is by giving him a toy filled with pokénip every time he brings home a new pokémon as a “reward,” then releasing his catch whenever he’s not looking. This may sound a bit backwards, as rewards are typically reinforcements for good behavior, but eventually, purrloin will want the reward over the pleasure of teaching you something, which means he may eventually switch to presenting you with any object (or even the empty toy) whenever he wants pokénip.
Best of luck, anonymous.