for few days they will feel uncomfortable. they try to open it. sometimes scared and jump around when the collar is on their neck. but its get well after that, they will feel comfortable with it. just make sure it is not too tight. i will open it sometimes and leave it without the collar few days. sometimes will not use it

no.. actually the problem will occur is territory management 101

in your case, all you need to do is neuter the male cat, so another male cat won't kena rogol.

the problem of having 2 or male cat in one house is territory problem. It is the nature of a male cat to fight over territory. Unless u have 2 or more male cat that grew up together from kitten.

Like my case, there is 3 male cats here. Adult A, Kitten B, Kitten C.

Adult A is the first male cat, so i brought Kitten B when he is very small like 2 weeks. I let the Adult A watch Kitten B grew up in cage. When Kitten B is about 3 months, i let him play in the house, with Adult A watching. Im lucky because Adult A is a type of cat that do not disturb other cat. So they grew up together in the same house and have no territory problem.

Then suddently Kitten C come over, his age is about 6-7 month that time. Both Adult A and Kitten B was so angry and start bully Kitten C. I have to put Kitten C in cage, and Adult A and Kitten B was like surrounding that cage, and start to slap the cage. woah!

That is the reason why, some people do not want to get too many Male cats in one house

-----

Same goes to fish.. like guppy.. they said, 1 male need atleast 3 females. If you have 2 males, and 2 females. the males will kill each other, or the male will just kill the females. Gosh!  no wonder my guppies keep dying

yes normally the adult will afraid of kitten because they are naughty... female kitten pun boleh tahan nakal. as long as it is a kitten, they will always be naughty

if from shop blackwood will be expensive. and they sell in small small pack. the one that i get from bulk purchase is, the one they order direct from the factory. so when they buy in bulk like 200kg they get special price.

if you do not want to join the bulk purchase, you can go for IAMS or PROFORMANCE = for sure they are much cheaper than blackwood retail price.